Add tabbing for files actions menu

[nfebe]

Resolves : #36989

Before

before.webm

After

after.webm

[nfebe]

I should have put this in draft first, sorry about that folks but this is not ready for review as the implementation need to be tested with at least one modal for correctness and in this case that is #36989. (See todo in PR description)

[Pytal]

I believe this is functionally identical to https://github.com/focus-trap/focus-trap?

If so then we can use the lib instead i.e. #37780

[nfebe]

Thanks @Pytal! Did not know of this. Even though it was tricky to write this, that looks solid!

One question, focus-trap library deactivates clicks outside the focus container. The way most modals and elements that need focus trap is when you click outside the container, the modals would close, would the new behavior be okay? (It's configurable)

[nfebe]

This only works when the user clicks on the same button that triggered files menu. If the user clicks else-where on the document which closes the menu, proper focus is not restored.

PS : @susnux @Pytal do you know where "background click closes menu" is handled?

[skjnldsv]

Kinda the same, files to vue already fixes it 🙈