Validate conditions at the end of e2e tests

[sbueringer]

We recently noticed that after a CAPI upgrade some conditions didn't look as expected (e.g. Available was false).

We fixed the issue and then added validation of some conditions to the clusterctl upgrade tests in: #11948

So now we are checking Ready and Available conditions on Clusters and Machines.

We should add the same check to the end of other e2e tests as well (maybe even all or most of them).