Self-contained State module

[imalygin]

This is the logical continuation of the Public Merkle API initiative (#10988). Also, it overlaps with #14772.

There are two main goals of this Epic:

1. Remove all platform specifics from the State module
2. Add state lifecycle management to the State module in an generic (non-platform specific) way

Currently, a Block node would have to not only use the swirlds-state-api module but also swirlds-platform-core as a dependency, which, in turn, contains functionality that is not relevant in the context of the state (consensus, gossip, transaction handling).

We need a State module that has not only a set of API interfaces but also all the necessary implementations to represent the full Merkle state.

Platform Dependency Removal

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1. Introduce swirlds-state-impl module #16221
   Platform +1
   
2. Clean-up MerkleStateRoot from the deprecated PlatformState #16380
   Platform +1
   
3. Create a design doc outlining all the neccesary changes required for this module #16193
   Platform +1
   
4. Remove State class #15638
   Platform Platform Data Structures Tech Debt Reduced +3
   
5. Refactor MerkleStateRoot - extract lifecycle-related code to a separate class #16322
   Platform +1
   
6. Migrate state-related classes from swirlds-platform-core to swirlds-state-impl #16223
   Platform +1
   
7. swirlds-state-api module should not depend on Hedera node HAPI module #15623
   Platform Tech Debt Reduced +2
   
8. Remove MerkleRoot interface #16436
   Platform +1
   
9. Remove dependency on swirlds-state-impl from swirlds-platform-core #16568
   1 of 2
   Epic Platform +2
   
10. Rename MerkleStateLifecycle #16569
    Platform +1
    
11. Move Filtered*State and Wrapped*State to swirlds-state-api #16589
    Platform +1
    

Lifecycle Management

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1. Check all usages of getReadablePlatformState() for thread safety #15620
   Platform +1
   
2. Drop support of INIT_STATE_FILE_VERSION #17023
   Platform Tech Debt Reduced +2
   

[poulok]

We discussed at DevCon that this State Module may also need to include the management of states similarly to the SwirldStateManager which keeps a thread-safe reference to the mutable state and the latest immutable state, but more than that. It could include logic that does things like ensure that only a single loaded state is mutable and that it is always the latest one even if the user of the module loads another, older state from disk.

[thenswan]

The current plan of moving forward with this epic:

1. Remove State class #15638
2. Refactor MerkleStateRoot - extract lifecycle-related code to a separate class #16322
3. Remove MerkleRoot interface #16436 (blocked by previous step).

[imalygin]

Moved tasks related to the state lifecycle management to #17540