Create or editing a bookmark while a full sync is occuring loses changes

[calpaterson]

Description

Full sync interrupted normal bookmarking and things don't go into the local db correctly

Steps to reproduce

1. Wait for a full sync to start
2. Create a bookmark
3. Check that bookmark on quarchive.com

Expected result

Bookmark has been uploaded successfully

Actual result

Bookmark not uploaded

Additional details

Deleting and recreating seems to fix it, but not very cleanly - other exceptions are raised