Add new columns to the `system.topology` table: `shard_count` and `ignore_msb`. When a node bootstraps or restarts and observes that the values stored in `topology` are different than the local values, it updates them. This is done in the `update_topology_with_local_metadata` function (the 'metadata' here being the two values).
Additional flag persisted in `system.scylla_local` is used to safely avoid performing read barriers when the values didn't change on node restart. A comment in `update_topology_with_local_metadata` explains why this flag is needed.
An example use case where `shard_count` and `ignore_msb` are needed is creating CDC generations.
Fixes: #13508Closes#13521
* github.com:scylladb/scylladb:
raft topology: update `release_version` in topology on restart
raft topology: store `shard_count` and `ignore_msb` in topology
a8f8f9f0ea