(PUP-3081) Remove dependencies on specific notice

This family of tests was applying manifests and predicating success
on a specific notice. The wording of the notice was changed which
broke these tests. But this also exposed that testing for this message
wasn't needed anyway - there are other steps in these tests that
do a real check for success/failure.

While I was in there I added some blank lines between test steps,
so that it's not quite such a wall of text. It's a bit more readable
now (I hope).
(PUP-3081) Check for absence of warnings rather than specific notices

For this ticket we changed the Notice associated with catalog application.
This test had a very specific regex it tested against, but the real issue
it was testing for was the absence of warnings rather than precise fidelity
to a particular pair of notices.

So this commit updates the regex to just check for the absence of warnings.
Merge pull request #3130 from kylog/issue/pup-3081/acceptance-fixup

Issue/pup 3081/acceptance fixup