TOT-37: Add UI feature to manage AOI user assignment and their role therein.

Purpose

The purpose was to add an admin view for viewing a list of users associated with a selected AOI. Role values can be updated and users with a pending role can be approved or removed.

The following was requested: "Link to the /adm-panel page for validating alerts"

But, rather than linking to the adm-panel, the "Alert Management" content of that component was nested within the first tabbed view of the restructured Admin Page.

Related Issues

Closes TOT-37

Screenshots, Etc.