Support dolt schema update-tag in SQL

[fulghum]

Column tag collisions can happen if schema changes are made on different branches and the new column tags happen to use the same tag id. From the CLI, there is a path for customers to unblock themselves by using the dolt schema update-tag command, but we don't support this via SQL today. We should provide a stored procedure that exposes the same functionality so that customers can unblock themselves if they do hit this.

[zachmu]

Alternate proposal: kill tags

#7772