Fix upgrade tests from #9704 that are still failing

The first things to do on this ticket would be to commit Tyler's branch (https://github.com/thobbs/cassandra-dtest/tree/8099-backwards-compat) to the dtests so cassci run them. I've had to do a few minor modifications to have them run locally so someone which access to cassci should do it and make sure it runs properly.

Once we have that, we should fix any test that isn't passing. I've ran the tests locally and I had 8 failures. for 2 of them, it sounds plausible that they'll get fixed by the patch of CASSANDRA-9775, though that's just a guess. The rest where test that timeouted without a particular error in the log, and running some of them individually, they passed. So we'll have to see if it's just my machine being overly slow when running them all.