DDL + script to dump it

Will be used in the future to easily sync and track DDL changes
e.g. if we want to drop a column, we just commit the DDL with the
dropped column, this way we track in git the DDL changes and can keep
commits and PR complete when a change impact both the code and the
database.

Did this because I want to propose some PR with DB changes and it's easier this way to communicate the changes in a pack.