Alternator is a coordinator-side service and so should not access
the replica module. In this series all but one of uses of the replica
module are replaced with data_dictionary.
One case remains - accessing the replication map which is not
available (and should not be available) via the data dictionary.
The data_dictionary module is expanded with missing accessors.
Closes#9945
* github.com:scylladb/scylla:
alternator: switch to data_dictionary for table listing purposes
data_dictionary: add get_tables()
data_dictionary: introduce keyspace::is_internal()
4aa9e86924