feat(meta): use PutSequential table locks (#19913)

# Summary

Table lock acquisition now uses a v2 meta keyspace backed by PutSequential, separating rolling-upgrade lock rows from the old format and avoiding the shared revision-generator contention in the old LockApi.

# Details

- Add a v2 table-lock key layout under `__fd_table_lock_v2` with generated sequential revision suffixes and document the acquire algorithm.
- Route default catalog table-lock operations and predecessor watches through the v2 keys so lock holders wait on the new queue.
- Remove the old meta LockApi export and update schema API coverage to assert v2 lock ordering, TTL cleanup, acquired state, and lock listing output.

Author: drmingdrmer