Tidy up `Edit in json` footer entries (#41890)

Before:
<img width="350" height="109" alt="before"
src="https://github.com/user-attachments/assets/d5d3e6bd-3a65-4d7d-8585-1e4d8f72997f"
/>

After:
<img width="310" height="103" alt="after"
src="https://github.com/user-attachments/assets/40137084-7323-4a79-b95b-a020c418646b"
/>

* All items got a keybinding label
* All items were made of a non-small size, to match the text size in the
right button
* Keybindings are rendered as disabled for disabled buttons

Release Notes:

- N/A

Co-authored-by: Lukas Wirth <lukas@zed.dev>
4339c772e4Kirill Bulatov committed on 11/4/2025, 10:49:47 PM· committed by GitHubparentba7ea71
2 files changedLine totals unavailable