Only show Open Accessible View when there is an accessible view to open

[andreamah]

Testing #191344

I'm not sure if you considered this already, but it would be nice to have the Open Accessible View in the command palette only when you're focused on something that supports it. When running the command in a random place, it just does nothing, which might be confusing to people who are trying to learn what the command does.

[meganrogge]

We want it in the command palette for discoverability purposes, but I agree with you that a no-op could be confusing.

[meganrogge]

This would be involved to fix because currently, we don't have a concept of focusedItemWithAccessibleView. We might have this one day when there's an audio cue played to indicate that.