The token ring table is a virtual table (`system.token_ring`), which contains the ring information for all keyspaces in the system. This is essentially an alternative to `nodetool describering`, but since it is a virtual table, it allows for all the usual filtering/aggregation/etc. that CQL supports.
Up until now, this table only supported keyspaces which use vnodes. This PR adds support for tablet keyspaces. To accommodate these keyspaces a new `table_name` column is added, which is set to `ALL` for vnodes keyspaces. For tablet keyspaces, this contains the name of the table.
Simple sanity tests are added for this virtual table (it had none).
Fixes: #16850Closesscylladb/scylladb#17351
* github.com:scylladb/scylladb:
test/cql-pytest: test_virtual_tables: add test for token_ring table
db/virtual_tables: token_ring_table: add tablet support
db/virtual_tables: token_ring_table: add table_name column
db/virtual_tables: token_ring_table: extract ring emit
service/storage_service: describe_ring_for_table(): use topology to map hostid to ip