FEATURE: Overhaul of admin API key system (#8284)

- Allow revoking keys without deleting them
- Auto-revoke keys after a period of no use (default 6 months)
- Allow multiple keys per user
- Allow attaching a description to each key, for easier auditing
- Log changes to keys in the staff action log
- Move all key management to one place, and improve the UI

app/serializers/api_key_serializer.rb

@@ -4,8 +4,11 @@ class ApiKeySerializer < ApplicationSerializer
 
   attributes :id,
              :key,
+             :description,
              :last_used_at,
-             :created_at
+             :created_at,
+             :updated_at,
+             :revoked_at
 
   has_one :user, serializer: BasicUserSerializer, embed: :objects