server: enhance the ts check considering commit timestamp

[cfzjywxk]

Enhancement

After a write transaction is committed, TiDB, as the transaction coordinator, knows the commit_ts used for the write transaction. This timestamp can be used as a reference to check the validity of subsequent read requests’ read_ts. In theory, all read requests occurring after the write transaction should use a read_ts greater than the previous known transaction’s commit_ts.

This approach could help to expose issues like #56809 more quickly.

Besides, this timestamp could be considered for updating the tidb_low_resolution_ts with the known valid timestamps encountered.