[FEA] Modeling language integration

[anandhkb]

• Finish cvxpy and scipy
• Handoff Julia from Rajesh
• Performance optimization on those that we do have
• Can we identify and resolve bottlenecks?
• Add nightly or PR tests for the integrations to our test suite
• Additional notebooks for third-party modeling languages

[anandhkb]

Finish cvxpy and scipy - DONE

Handoff Julia from Rajesh - DONE

@afender @rgsl888prabhu @tmckayus for viz