Is your feature request related to a problem? Please describe.
Difficult to find users to delete from a group when large number of members

Describe the solution you'd like
The fixes for

• Performance Issues with Groups having many EPerson members DSpace#9052
• "Edit Group" page always requests all member subgroups and EPersons. This has bad performance for large groups. #2512

split the members list of a group into current members and not-yet-in-group list of searchable members to solve issues loading members of large groups.

But this currently makes it very hard to remove a specific member from a group with a large number of members:

• The list of current members is not searchable or logically (eg alphabetically on name or email) sorted, so to find a member to delete you have to page through pages & find them
• On the EPerson page itself you can not remove the user either, it just lists the groups (as links to the group page) the user is a member of

Ideally the list of current members on the edit group page is searchable; and the Edit EPerson page allows (admins) to delete person from groups it is a member of without having to go to that group page.