[Feat]: add search bar to the "add members" UI for group membership

[lanedsmu]

The group "add members" UI lacks a search bar, which makes it harder to use than the share application UI.

Group member management is complicated by the fact that the add member UI for user groups lacks a search bar. While it's possible to utilze the browser search to find a user, this is a somewhat counterintuitive use for browser text search.

Unifying the group member add UI and share app UI, so that they have parity, or--better?--actually share the same UI, would make a more user-friendly experience. This is especially true when a user list grows to many hundreds or thousands, as might be expected in an enterprise environment.

[lanedsmu]

This is also related to another issue that I forgot I'd opened: #1631

[BobLouderback]

Perhaps add a sort option to the table headers as well?