Users page lazy multiselect group dropdowns
Instead of pre-rendering all multiselects with lots of group entries,
the current groups are now displayed as simple labels.
Behind the labels there is a pencil icon like for other fields.
When clicking the pencil icon, the dropdown will be spawned and will
open itself.
Upon closing of the dropdown, the label comes back with the updated
selection and the dropdown is destroyed.
Extra non-available groups also in list
Fix group sorting in user list group selection