Add support for all SQL types in migration system

[k98kurz]

Is your feature request related to a problem? Please describe.

The focus of the library is sqlite3, but broader compatibility would make the library more useful.

Describe the solution you'd like

Add more SQL types into the migration system. Planning out those types and how to implement and test them will be done in the comments after other planned work is complete.

Describe alternatives you've considered

Telling MySQL and PostgreSQL users to go pound sand, but I use both of these often enough that I'd be talking to myself, and I wouldn't appreciate the rudeness.

Additional context

• MySQL data types
• PostgreSQL data types