Desktop: Fixes #13579: Rich Text Editor: Make cursor jump during editing less likely

[personalizedrefrigerator]

Summary

This pull request adjusts when the Rich Text Editor's cursor location is restored from the global redux state. Previously, the cursor location was restored when the TinyMCE ContentSet event was emitted and when rendering completed. With this change, the cursor location is restored only when switching notes.

May fix #13579.

Testing

Screencast.from.2025-10-30.10-24-49.webm

The above screen recording demonstrates:

1. Opening a note in the Rich Text editor.
2. Selecting text.
3. Switching to a different note.
4. Switching back to the original note.
5. Verifying that the text is still selected.
6. Switching to a different note.
7. Positioning the cursor somewhere in the middle.
8. Switching to a different note, then switching back.
9. Verifying that the cursor is still positioned in the position from step 7.
10. Opening the note in a new window.
11. Focusing the editor with ctrl-shift-b.
12. Moving the cursor to scroll the selection into view.
13. Verifying that the cursor is positioned in roughly the position from step 7.
14. Making a change to the note (adding ...).
15. Switching back to the main window.
16. Verifying that the cursor is positioned where it was placed in step 7 (just before the ...s added in step 14).