[feature request] Add Python stubs to pyds library

[pkot]

Generating simple python stubs for Deepstream Python bindings and bundling them with your package would make app development much easier.

Proper stubs enable proper code completion and make some type checks possible.

In my case to get stubs I used stubgen from mypy

stubgen -m pyds --output ~/.local/lib/python3.10/site-packages

but for pyds pybind11-stubgen may be better

[pkot]

But unluckily in my case I was not able to get descriptions from bindings/docstrings/functionsdoc.h maybe these stubs should be generated during binds build process.