add `toggleSuggestionFocus` command for simple suggest widget

[meganrogge]

We want to make suggest widget details kb focusable so screen reader users can read them like they can in the editor

[meganrogge]

cc @Tyriar

[meganrogge]

turns out this is pretty tricky to do - because we hide the suggest widget on terminal blur, moving focus to the element closes it. I added a hack for this that works around it, but don't think it's a good idea because then it won't hide in certain cases when we want it to.

[meganrogge]

Open terminal suggest by typing something like ls.

Press ctrl+space to show the docs.

Press ctrl+alt+space to toggle doc focus between that and the terminal.