Expand relative period options

[KaiVandivier]

Consider a table in which the rows correspond to the last 12 months since the time of report generation. In the Data Visualizer app, this can be achieved by creating a table using the 'Last 12 months' relative period, but it's not currently possible to make such a table in this app here.

The existing tools in this app could create a report using several months as periods, but they must be statically defined.

There are two ways these relative period options can be implemented:

1. Add options in the period selector dialog to choose periods like '2 months ago,' '3 months ago', etc.

• Pro: more options for choosing periods. Maybe a user wants the last two months, instead of the last quarter.
• Con: slow to define the appropriate rows in the case of 'last 12 months' - lots of user work

2. Detect when multiple periods are used and expand the table with the appropriate content upon generation (e.g. define a row with a period 'Last 12 months' in the table editor; then, when the report is generated, that row is expanded to 12 rows for the appropriate months)

• This may interfere with a user's wish to use multiple periods as a filter, for example showing data in a cell for two years combined. Maybe it should only work for relative periods, and static periods should act as filters.
• This would result in less user work.