storage_service: init_server: replicate_to_all_cores after updating token_metadata
storage_service: init_server: replicate_to_all_cores after updating token_metadata

Currently the replication to other shards happens later in `prepare_to_join`
that is called in `init_server`.
We should isolate the changes made by init_server and update them first
to all shards so that we can serialize them easily using a lock
and a mutable_token_metadata_ptr, otherwise the lock and the mutable_token_metadata_ptr
will have to be handed over (from this call path) to `prepare_to_join`.

Signed-off-by: Benny Halevy <23c997c90eb8537635e9392d48e7af1bf1b2ca22@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla