Remove unused tags from the assign tags dropdown list and filters

A-M to cleanup; see UITAG-24 (changed from story to Feature) - remove the duplicate feature, but make sure all notes are retained and links are updated

Purpose: To remove unassigned tags from the central tag list, so that typos do not persist in the dropdown list users see when assigning tags

As a staff person
In the list of possible tags to assign to records, I only want to see tags that have previously been assigned to records, or ones I am newly creating at that moment
So that unassigned tags (often typos) do not clutter the tag list

NOTES
This may need to be adjusted when we get to Tags-Central Management (UXPROD-775) if a library chooses to create centralized tags that are not yet assigned to any record
Per Khalilah, this will require both front-end and back-end work

Scenarios

1. Scenario 1
   • Given the tags dropdown list a user sees when assigning tags or filtering by tags
   • When the user views the list
   • Then delete (remove) tags that have not been assigned to any record in any app (i.e. remove them from the central tag list)
   • Which means that every tag showing in the dropdown is assigned to at least one record in the FOLIO tenant
2. Scenario 2
   • Ensure automated testing coverage for this new code is 80% plus and confirm with screenshot