Provide a one-click option for the Admin to invalidate a member's votes and nominations

Currently the process to invalidate a member's votes and nominations (in case of a revoked membership or relinquishment) is complex and manual; the admin must:

1. Find all nominations associated with the member and mark them invalidated
2. Find all ranks associated with the member and mark them invalidated
3. Mark the member's advisory votes as invalid
4. Remove the member from the nominating and voting group

This should be possible with one click from the member page, with a confirmation about what will be changed.