Increase compatibility with mysql
1. Added two system tables files and partitions
2. Improved the return logic of mysql error code to make the error code more compatible with mysql
3. Added lock/unlock tables statement and show columns statement for compatibility with mysql dump
4. Compatible with mysqldump tool, now you can use mysql dump to dump data and table structure from doris
now use mysqldump may print error message like
```
$ mysqldump -h127.0.0.1 -P9130 -uroot test_query_qa > a
mysqldump: Error: 'errCode = 2, detailMessage = select list expression not produced by aggregation output (missing from GROUP BY clause?): `EXTRA`' when trying to dump tablespaces
```
This error message not effect the export file, you can add `--no-tablespaces` to avoid this error
52ebb3d8f5