break comment "edited at" block out of the note-text element to prevent issues w…

What does this MR do?

Moves "edited" text below a note into its own element apart from rendered markdown to prevent issues when it is preceded by an inline text node.

Are there points in the code the reviewer needs to double check?

to reproduce the bug, add text immediately following an image in a note's markdown like so:

![foo](/uploads/c6f86574e5c3b5b73e91eeccbcb06fe6/foo.png) test text here

then edit and save the note.

Why was this MR needed?

Screenshots (if relevant)

Before:

After:

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #25155 (closed)