Add support to replicate-rewrite-db filters

Filters like replicate-rewrite-db can't be used with pt-table-checksum. I've tried to avoid the problem of "USE" with the parameter "--replicate-database" from pt-table-checksum. But it doesn't work as a workaround because the queries to run the checksums still specify the fully qualified table names.

--replicate-database is primarily meant for replication filters like do-db and ignore-db but rewrite-db is not a filter like the others, and ptc isn't designed to handle it. We would need another option like --[no]database-qualified-tables, so you could specify --no-database-qualified-tables and let rewrite-db do its work based on the current/default db.