Enhancement: Send focus to "Add people" btn after closing Add/Edit panels

We've started sending the focus to "Add people" button after the `Add` panel in the people accordion has been closed.
Also, when editing a share the focus jumps back to the "Edit" button in the respective share after cancelling or 
confirming the action.

https://github.com/owncloud/web/pull/5129
https://github.com/owncloud/web/pull/5146
