[BUG] range types not supported

[rintaun]

Describe the bug

Unknown type detected: 'int4range'. You have either disabled generation of the type or this is a bug.

Reproduction
Create a column with a range type, e.g. int4range and attempt to generate types.

Expected behavior
A range type should generate a type of [type, type] | [null, type] | [type, null]

Additional context
It might also be necessary to add support for range types to DBDataSource, but I'm not sure whether slonik supports them out of the box. Some testing may be necessary.