Support `ALTER TABLE .. ADD CHECK` statements

It appears that SQL statements of the following form are failing:
```sql
ALTER TABLE test1.test2 ADD CHECK (active IN (0, 1));
```
```
line 22 column 34 near \"CHECK (`active` in (0,1))\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4\"
```

This error is occurring within pingcap/parser on the currently pinned version; however, this is supported in the latest version