Allow control over whether to use model name or db name

[michaelaltmann]

When a schema has models that are mapped to database tables using the @@Map function, allow the user to decide whether to generate the diagram using model name or db table name.

[michaelaltmann]

Deciding between model name and db name should also apply to fields (aka sb columns).

[keonik]

I wanted to do this but just haven't had time. I personally would rather see all the prisma variable names so I would default to that.