Consider not having all toolbar items in the Tab order

relates to #277496: [EPIC] Accessibility issues/suggestions (I guess)

We've been considering using F6 for this, that seems standard in some other applications. But yes, this is definitely something we've been wanting to do at some point.

Ideally:

• F6 / Shift+F6 would treat all toolbars as a single container.
  • Press to go from the toolbars to the score, Mixer, Inspector, etc.
• Tab / Shift+Tab would treat each toolbar as a separate container.
  • Press to go from one toolbar to another (e.g. File Operations to Note Input).
• Left / Right would enable navigation within the current toolbar.
  • Press to go from one button to another (e.g. Open to Save).

This has been fixed in MuseScore 4 by implementing the behaviour I described above.

Automatically closed -- issue fixed for 2 weeks with no activity.