Add support for PostgreSQL's geometric point type

[chiumichael]

Motivation

Entities generated by sea-orm-cli currently cannot handle PostgreSQL's Point type since this is not yet implemented.

Proposed Solutions

Additional Information

https://www.postgresql.org/docs/current/datatype-geometric.html

[AbhinavMir]

Could you provide an example of how you'd like to see this done?

Other geometric types can inherit from Point. I'm sure adding the data type support isn't too hard. I imagine we'll modify the codebase to include something like: Value::Point(v) => to_sql!((v.x, v.y), (f64, f64))

Can someone scope/check this approach before I implement it?