Update `test_connections_parameters_auto_update` to also check that the
scheduling group of given connections is appropriately changed when a
different service level is assigned to the user that the connection uses
for authentication.
Apart from that, more tests are added:
- Check for the logic that forbids setting shares for a service level
until all nodes in the cluster are upgraded
- Test for handling the case when there are more scheduling groups than
it is allowed (it might happen after upgrade from a non-workload-prio
version)
- Regression test for a bug where less scheduling groups could have been
created than allowed due to some metrics not being renamed on
scheduling group name change.
473bb44722