Added new annotations for the externalsharescontroller class
* @NoOutgoingFederatedSharingRequired
* @NoIncomingFederatedSharingRequired
By default both are required for all functions in the
externalSharesController.
A proper exception is thrown and then a 405 is returned instead of the
default error page. Since it is only an API endpoint this makes more
sense.
Unit tests added and updated
1. Allows to set a timeout (though still not perfect but way better than before)
2. Allows to have unit tests
3. I also added unit tests for the existing controller code
4. Corrected PHPDoc on IClient
