Response example generation for XML and CSV

[rishitank]

What/Why/How?

As part of implementing api-docs at Adthena, we had the need to auto-generate response examples for XML and CSV based on the OpenAPI schema provided.

• This PR implements XML and CSV response example generation for Redoc if a response example is not provided.
• The code for XML generation was adapted from RapiDoc's implementation and ported over to TypeScript.
• The feature can be enabled via a redoc option.

Reference

Testing

Screenshots (optional)

Check yourself

• [x] Code is linted
• [x] Tested
• [x] All new/updated code is covered with tests