_validate_single_function_inputs  has much the same logic as the original is_valid_inputs function.

We don't have OpenAI Function Calling Dynamic Routes as an alternative to regular dynamic routes any more, it is now the default.

Simplified __call__ in route.py as we don't have 2 separate methods of treating dynamic routes anymore.

This reverts commit 7bb47b3efa90c8ea21b7ac756158a7f70f4bc04d.