Add a deny option for the proxy default role (#24145)

* backend

* frontend

* docs

* fix none default role casing and name reserved roles in the error

* reserve every casing of none as a role name

docs/static/frigate-api.yaml

@@ -62,6 +62,9 @@ paths:
                 type: string
         '401':
           description: Authentication Failed
+        '403':
+          description: Access Denied (proxy user resolved to a default role of 
+            'none')
       security: []
       x-required-role: public
   /profile: