Replacing `restrict_replication_simplestrategy` config option with
2 config options: `replication_strategy_{warn,fail}_list`, which
allow us to impose soft limits (issue a warning) and hard limits (not
execute CQL) on replication strategy when creating/altering a keyspace.
The reason to rather replace than extend `restrict_replication_simplestrategy` config
option is that it was not used and we wanted to generalize it.
Only soft guardrail is enabled by default and it is set to SimpleStrategy,
which means that we'll generate a CQL warning whenever replication strategy
is set to SimpleStrategy. For new cloud deployments we'll move
SimpleStrategy from warn to the fail list.
Guardrails violations will be tracked by metrics.
Resolves#5224
Refs #8892 (the replication strategy part, not the RF part)
Closesscylladb/scylladb#15399
8c464b2ddb