Add optional parameter SNAPSHOTTED to SHOW READYSET TABLES

[altmannmarcelo]

Description

If a user has a lot of tables to replicate and does not want to replicate all, they might use replication filters to not snapshot some tables. Currently SHOW READYSET TABLES does not provide a way to filter out tables that are not replicate.

Similar to SHOW PROXIED [SUPPORTED] QUERIES, we should add SHOW READYSET [SNAPSHOTTED] TABLES

Change in user-visible behavior

Requires documentation change

Yes, update https://readyset.io/docs/reference/command-reference#readyset-tables