Changed behaviour:

- Minor change to some tests to add Debug flag to ensure that IvsLam outputs that are being checked are actually created. For group workspaces this is currently true anyway at the moment but might not be going forward.

Add new unit tests:

- Check default output names are correct.
- Check that user can override default names.
- Check both with and without debug outputs.

Also fixed ambiguous overload in reflectometry helpers.

Re #24564