TRUNK-4315: Added check for newly created providers and edited test vali...

...date_shouldNeverHaveBothPersonAndNameSet()

https://issues.openmrs.org/browse/TRUNK-4315

The check adds an error message if both provider name and person id are specified.
I modified the validate_shouldNeverHaveBothPersonAndNameSet() test because the stub violates the above rule
and therefore an error should be displayed to the user