SQLModelGenerator does not respect table names

[brianmcburney]

Love the addition of the SQLModelGenerator. However the generated models transform the table names in undesired ways (e.g. some_random_table becomes somerandomtable).

Removing render_class_variables from the SQLModelGenerator class, or simply calling super().render_class_variables there fixes the issue. DeclarativeGenerator.render_class_variables adds the __tablename__ class variable, which is supported by SQLModel, see here.

I'm happy to open a PR, but I'm not sure if this would have unintended consequences (or if there's a better way to accomplish this).

[agronholm]

I am in the middle of a big refactoring now. It's best to leave such PRs until after that work has been committed.