Reduce number of NodePropertiesWereSet events during inline editing

[bwaidelich]

Currently when inline-editing a text in the Neos content module, changes are sent to the server during typing leading to sometimes multiple NodePropertiesWereSet properties per second!

This produces needles load and makes rebasing, replays etc. less performant.

A solution might be to compress similar NodePropertiesWereSet events during rebase (see #4263).

But it might be more sensible to avoid the similar commands to be triggered already on the client side:
We could postpone the /neos/ui-services/change request to when the editor has actually finished typing (e.g. on blur and or navigation).
Obviously this is more involved and concerns UX. E.g. the pending changes should probably kept in the local storage such that they are not lost if the browser is closed etc.

Note: I could imagine unsaved text to be highlighted somehow: