Configurable timeout for External Authorization service
From the original issue #4216 (closed):
A failed response should display an error with the JSON "reason" response displayed if available.
- If the service times out, display "External Policy Server did not respond".
- The timout value should be configurable and default to 500ms
Configurable timeout was not implemented in !3709 (closed) to cut the scope of an already huge MR.