Support ALTER TABLE .. ADD CHECK statements

[jonahgeorge]

It appears that SQL statements of the following form are failing:

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

[jonahgeorge]

This requires updating to the latest TIDB and pingcap/parser version. Unfortunately that version removes support for parsing gbk charsets and also changes the default column size.