Partial syncs cause duplicate changes/noise

[myieye]

Describe the bug
If a sync fails after some fwdata changes have been applied to crdt, then those changes are not reflected in the project snapshot. I.e. they are not considered to have been applied to crdt. As a result, the next sync will apply the same changes again.

This is mostly harmless. Crdt is designed to handle duplicate changes:

• Create Changes will have no effect (and thus result in a new latest snapshot that is identical to the previous latest snapshot)
• Edit Changes will simply apply the same changes again (and thus also create redundant snapshots)

So, the only downside of this is that it can result in a lot of (1) noise in the project activity and history views and (2) database clog.

Expected behavior
A sync should not repeat changes that have already been applied.