Restrictions on foreign keys on stored generated column

This is a separate but related issue to #11065, where we discovered MySQL has restrictions on foreign keys on columns that are referenced by stored generated columns. MySQL also has restrictions on foreign keys on stored generated columns themselves.

From [MySQL docs](https://dev.mysql.com/doc/refman/8.4/en/create-table-foreign-keys.html#foreign-key-referential-actions):
> A foreign key constraint on a stored generated column cannot use CASCADE, SET NULL, or SET DEFAULT as ON UPDATE referential actions, nor can it use SET NULL or SET DEFAULT as ON DELETE referential actions.