Creating a materialized view or a secondary index in a tablet-based
keyspace requires that the user enabled two options:
* experimental feature `views-with-tablets`,
* configuration option `rf_rack_vaid_keyspaces`.
Because the latter has only become a necessity recently (in this series),
it's possible that there are already existing materialized views that
violate it.
We add a new check at start-up that iterates over existing views and
makes sure that that is not the case. Otherwise, Scylla notifies the user
of the problem.
(cherry picked from commit 288be6c82d)
2e2d1f17bb