Add wayang-api-json and wayang-api-python to create WayangPlans from python

[juripetersen]

This PRs description can be found in one of our blog posts:

https://wayang.apache.org/blog/wayang-python-api

[juripetersen]

This PR will also entail an issue arising with typing. Currently the interchange format between python and wayang is mainly handled by serializing strings and parsing them to the desired type in the udf. It is of course desirable to add type hints to operators that allow the parsing to happen implicitly. The issue will be added after merging the PR.

[2pk03]

@zkaoudi @kbeedkar - pls review too before we merge.

[kbeedkar]

looks good to me +1