Improve test cleanup methods to allow parallel integration runs

[Temikus]

Currently, we cannot aggressively parallelise integration tests due to possibility of cleanup routines for each test instance stepping over each other.

3 things are probably needed:

• We need to pass a unique key id for the run to every workflow execution and target the cleanup on that.
• Set up a backup cleanup action that would ensure cleanup of objects outside of the test teardown routine (e.g. if tests error out).
• Set up a final backstop running every week or so to cleanup everything else that might get stuck accidentally so we don't overrun our CI bill.