feature: Add non-LLM guardrails

[christinaexyou]

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