add clear method in InMemoryStore

[DavidBadura]

Add a clear method to empty the in memory subscription store.

[github-actions]

Hello 👋

here is the most recent benchmark result:

SimpleSetupBench
================

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad1Event ()                     | 957.400μs (±0.00%) | 974.200μs (±0.00%) | -1.72%    | 34.266mb        | 34.274mb   | -0.02%      |
| benchLoad10000Events ()                | 49.514ms (±0.00%)  | 48.931ms (±0.00%)  | +1.19%    | 34.266mb        | 33.765mb   | +1.48%      |
| benchSave1Event ()                     | 963.300μs (±0.00%) | 914.000μs (±0.00%) | +5.39%    | 33.765mb        | 33.765mb   | 0.00%       |
| benchSave10000Events ()                | 227.157ms (±0.00%) | 225.021ms (±0.00%) | +0.95%    | 33.765mb        | 33.765mb   | 0.00%       |
| benchSave10000Aggregates ()            | 7.983s (±0.00%)    | 8.495s (±0.00%)    | -6.03%    | 33.765mb        | 33.765mb   | 0.00%       |
| benchSave10000AggregatesTransaction () | 4.834s (±0.00%)    | 4.889s (±0.00%)    | -1.12%    | 33.765mb        | 33.765mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

SnapshotsBench
==============

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad10000EventsMissingSnapshot () | 51.178ms (±0.00%)  | 49.334ms (±0.00%)  | +3.74%    | 33.836mb        | 33.836mb   | 0.00%       |
| benchLoad10000Events ()                | 887.400μs (±0.00%) | 895.200μs (±0.00%) | -0.87%    | 33.836mb        | 33.836mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

SubscriptionEngineBatchBench
============================

+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+
|                           | time (kde mode)                                   | memory                                     |
+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+
| subject                   | Tag: <current>    | Tag: base         | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+
| benchHandle10000Events () | 72.886ms (±0.00%) | 73.936ms (±0.00%) | -1.42%    | 34.234mb        | 34.234mb   | 0.00%       |
+---------------------------+-------------------+-------------------+-----------+-----------------+------------+-------------+

SubscriptionEngineBench
=======================

+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+
|                           | time (kde mode)                               | memory                                     |
+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+
| subject                   | Tag: <current>  | Tag: base       | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+
| benchHandle10000Events () | 3.164s (±0.00%) | 3.178s (±0.00%) | -0.45%    | 46.382mb        | 46.382mb   | 0.00%       |
+---------------------------+-----------------+-----------------+-----------+-----------------+------------+-------------+

PersonalDataBench
=================

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad1Event ()                     | 924.500μs (±0.00%) | 912.200μs (±0.00%) | +1.35%    | 34.895mb        | 34.895mb   | 0.00%       |
| benchLoad10000Events ()                | 84.938ms (±0.00%)  | 86.897ms (±0.00%)  | -2.25%    | 34.895mb        | 34.895mb   | 0.00%       |
| benchSave1Event ()                     | 1.503ms (±0.00%)   | 1.579ms (±0.00%)   | -4.77%    | 34.895mb        | 34.895mb   | 0.00%       |
| benchSave10000Events ()                | 257.026ms (±0.00%) | 251.283ms (±0.00%) | +2.29%    | 34.897mb        | 34.897mb   | 0.00%       |
| benchSave10000Aggregates ()            | 12.073s (±0.00%)   | 12.190s (±0.00%)   | -0.96%    | 34.895mb        | 34.895mb   | 0.00%       |
| benchSave10000AggregatesTransaction () | 9.046s (±0.00%)    | 9.110s (±0.00%)    | -0.71%    | 35.396mb        | 35.396mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

SimpleSetupStreamStoreBench
===========================

+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                                        | time (kde mode)                                     | memory                                     |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                                | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad1Event ()                     | 970.400μs (±0.00%) | 947.400μs (±0.00%) | +2.43%    | 34.862mb        | 34.862mb   | 0.00%       |
| benchLoad10000Events ()                | 56.444ms (±0.00%)  | 55.217ms (±0.00%)  | +2.22%    | 34.862mb        | 34.862mb   | 0.00%       |
| benchSave1Event ()                     | 978.800μs (±0.00%) | 1.062ms (±0.00%)   | -7.81%    | 34.862mb        | 34.862mb   | 0.00%       |
| benchSave10000Events ()                | 302.016ms (±0.00%) | 309.317ms (±0.00%) | -2.36%    | 34.862mb        | 34.862mb   | 0.00%       |
| benchSave10000Aggregates ()            | 8.123s (±0.00%)    | 8.176s (±0.00%)    | -0.65%    | 34.862mb        | 34.862mb   | 0.00%       |
| benchSave10000AggregatesTransaction () | 5.104s (±0.00%)    | 5.121s (±0.00%)    | -0.34%    | 34.862mb        | 34.862mb   | 0.00%       |
+----------------------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

SplitStreamBench
================

+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
|                         | time (kde mode)                                     | memory                                     |
+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| subject                 | Tag: <current>     | Tag: base          | time-diff | Tag: <current>  | Tag: base  | memory-diff |
+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+
| benchLoad10000Events () | 4.344ms (±0.00%)   | 4.301ms (±0.00%)   | +1.00%    | 37.072mb        | 37.072mb   | 0.00%       |
| benchSave10000Events () | 348.214ms (±0.00%) | 346.248ms (±0.00%) | +0.57%    | 37.145mb        | 37.145mb   | 0.00%       |
+-------------------------+--------------------+--------------------+-----------+-----------------+------------+-------------+

This comment gets update everytime a new commit comes in!