Validator: Add Uli Slur Validator

[baarish-tesu]

Is your feature request related to a problem? Please describe.
Lexical slur detection validator for Hindi and English as an input guardrail.

Describe the solution you'd like
This is rule-based and uses an extensive multilingual slur list developed by Tattle. Existing semantic slur detection largely effective for English. Tattle's slur list picks up on nuanced and changing usages of slurs in Hindi, English, and Hinglish.

Describe alternatives you've considered
Develop Semantic detection for slurs in Indian languages in Q2.