python wrapping of factory

[laroque]

PoA (based on slack discussion with Noah on #sidebar2):

• Wrap factory & base_registrar (in scarab/library/utility/factory.hh)
  • handle the registration in python
  • note that XBaseType = Nymph::KTProcessor and XArgs = const std::string& for all cases of interest
• write a python implementation of registrar which subclasses base_registrar. the user workflow is to then write a new KTProcessor subclass and a corresponding python registrar for that processor

[laroque]

Phone chat today:

• should not need to wrap factory, just base_registrar
• In Nymph, create a python_base_registrar which deals with the templating as above, and implements a create method which is able to create an instance of a python-implemented processor which is derived from KTProcessor
• Figure out how to access a toolbox's factory and call the register methods at runtime so that python-implemented processors can be used
• Probably need to extend the katydid Toolbox class in python to ensure that it is dealing with python processors/objects correctly (we discussed possible changes to the data object behavior which may require care in registering new slots for C++ processor implementations which need to receive signals from new python-implemented processors.

[nsoblath]

This was done (more or less, I believe) in Nymph in June 2022. Necessary classes are created here. And the Creator class is bound to Python here.