Describe the bug
Making multiple changes in quick succession on a new entry can lead to an exception.

When a new entry is created it doesn't have an ID. When making multiple changes quickly, the state of the ID is not managed well and as a result ends up geting included in the entry-diff. The differ doesn't know that the server doesn't like string IDs, but IDs should never be part of the diff anyway, because they should only get set by the server.

To Reproduce
Steps to reproduce the behavior:

1. Go to the Editor
2. Click on '+' (Create new entry). Note: an entry only actually gets created when some data is added to it.
3. Quickly click on "Add meaning" and then "Add example"
4. See error

Context
Reported by user: #1754 (comment)