Feat: Add support for response_format field in OpenAI Spec

[bhimrazy]

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

What does this PR do?

Fixes #196 .

PR review

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[codecov]

Codecov Report

Attention: Patch coverage is 94.44444% with 1 line in your changes missing coverage. Please review.

Project coverage is 80%. Comparing base (f73d30d) to head (3bb25b2).
Report is 1 commits behind head on main.

Additional details and impacted files

@@         Coverage Diff         @@
##           main   #197   +/-   ##
===================================
  Coverage    80%    80%           
===================================
  Files        13     13           
  Lines      1041   1058   +17     
===================================
+ Hits        835    851   +16     
- Misses      206    207    +1     

[aniketmaurya]

Looks great so far @bhimrazy 🚀 !! Let's check the Pydantic alias to avoid shadowing the BaseModel attribute.