* Fail if an empty string is set as src for copy module
Fixes#27363
* Cleanup task formatting on copy tests
Use multi-line YAML
Add debug statements with verbosity: 1 rather than leave them in there commented out.
* Add test for empty string as source
* Do more checks in order to add more specific errors messages
Add more integration tests for the various failure scenarios.
Cleanup some syntax on existing integration test tasks.