[TEST] Properly handle 5xx errors when `request` is being caught
Various exceptions should extend ServerErrorResponseException

These exceptions were previously extending the base \Exception, but
should ideally extend ServerErrorResponseException (which in turn
extends TransportException).  This predominantly helps with unit/integration
tests since the appropriate level of exception can be caught.

These exceptions are all the result of a 5xx error from Elasticsearch

Affected exceptions:

- NoDocumentsToGetException
- NoShardAvailableException
- RoutingMissingException