add python bindings for PIDHandler

[m-fila]

BEGINRELEASENOTES

• Added Python bindings for PIDHandler

ENDRELEASENOTES

Python test is selected tests from C++ version
Closes #396

[tmadlener]

Ah nice. I had mainly opened that issue as a reminder for myself not as a call to action ;)

What would be nice to check as well would be the constructors from frames, or from multiple collections via the static from methods. However, they clash with the from keyword from python. That was the main reason for me to not directly go to solve this ;) Would probably need some from_event and from_collections overloads on the c++ side to make things available on the python side in a working manner.

[tmadlener]

Adding the same creation functionality as is available in c++ in python via the from static functions seems not as straight forward as I had hoped. The problem is the python wrapper around the Frame that comes with podio. That makes overload resolution fail, and we would need to introduce a similar wrapper around PIDHandler here to deal with that, I think.

[m-fila]

There seems to be some problems with a lifetime when using pythonized std::optional and obtaining values from it 😐 For instance these seem to be not always the same

pid1 = handler.getPID(reco[0], 42)
pid1.value()

handler.getPID(reco[0], 42).value()

Possibly related to AIDASoft/podio#642

[m-fila]

I think a possible workaround for the problems with pythonized std::optional would be to add throwing interface and use it python bindings (and disable optional interface there)