feature: Add non-LLM guardrails

Did you check the docs?

• I have read all the NeMo-Guardrails docs

Is your feature request related to a problem? Please describe.

I want to be able to use regex and XGB models for input and/or output rails.

While the pre-existing LLM based rails can perform the same types of input/output rails as regex and XGB models, there is a lot of overhead resources (eg. GPUs, memory) required. Regex and XGB based rails can provide a more lightweight solution, especially for simple content_safety and sensitive_data_detection tasks.

Describe the solution you'd like

I want to add regex and XGB based input/output rails.

Describe alternatives you've considered

There are currently no non-LLM based input/output rails.

Additional context

No response

No files, tests, or entry points are named in the issue. Start by reviewing the existing input/output rail documentation and implementations, then determine how regex and XGB models should be configured and invoked. Done means both model types support input and output rails for tasks such as content safety and sensitive data detection without requiring LLM resources.