BR compatible with InfoSchemaV2

[Leavrth]

Modification List

InfoSchema V2 feature issue: #50959

1. Deprecate (*Meta).ListTables. It is called from br/pkg/stream/stream_mgr.go:buildObserveTableRanges to build log task ranges.
2. Don't upload entire table infos when start a log backup task. Done by br: error if the log restore has no full backup schema or id maps #54421
3. PITR restore and full restore checks whether there are user tables by calling GetExistedUserDBs. Switch to use a more efficient function.
4. Use (infoschema.InfoSchema).SchemaTables to get system tables instead of DBInfo.Tables. It's OK because the number of system tables is very small.
5. Maybe the cost of scanning the entire tables is very high, so IngestRecorder currently only search tables by table id of the recorded ingest index.