Summary:
This removes the need for any information drawn from the content of recent actions when loading a document.
The undo/redo system does need some facts about recent actions up front. But that system has an important restriction: only actions a particular client is known to have generated can be undone by that client.
So in this diff, as we store which client has performed an action, we also store the few pieces of metadata about that action that the undo/redo system needs: `linkId`, `otherId`, `rowIdHint`, `isUndo` fields. These are all small integers (or in one case a boolean).
An existing limitation is that information about which client has performed which action is stored in memory in the worker, and not persisted anywhere. This diff does not change that limitation, meaning that undos continue to not survive a worker transition. A reasonable way to deal with that would be to back the store with redis.
Test Plan: existing tests pass
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D3044
Summary: This moves enough server material into core to run a home server. The data engine is not yet incorporated (though in manual testing it works when ported).
Test Plan: existing tests pass
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2552
