For V2

[cmancone]

1. Break mutual dependency between model and backend to ease strict typing
2. Allow model to use properties with decorators for column definitions instead of the columns_configuration (although backwards compatibility might be nice - ditching columns_configuration can wait for V3, if that is ever needed)
3. Make parameters for column type builders explicit and strongly typed.
4. Ditch models.get_table_name
5. Make model.table_name a regular method rather than a class method
6. Combine model and models class?
7. Normalize how configuration is accessed across all classes
8. A route builder to ease construction of applications and especially make it so that configuring a handler has strict params/typing (probably not a breaking change so could be added later)
9. s/input_error_callable/input_error_callables/
10. Include model in input validation flow?
11. No implicit id column