Integration tests housekeeping

[joewesch]

To combat future additional copy pasta, I think we should make the following housekeeping changes to the integration tests:

• Move all set_fact items to main.yml (protip: tag always). This will make it obvious what fact names are already in use and which ones might be conflicting.
• Move all version conditional blocks (for full test suites) to main.yml. This should help make it obvious which tests should run for each minimum version. Any conditional blocks within files for only a sub-set of tasks can remain to keep the tests together.
• Remove all erroneous debug tasks.