Separate script for BMO component assignment and CASA backchannel comms

[claudijd]

I'd like to propose that we consider having two scripts instead of one. I believe adding the CASA logic to assigner.py is maybe overloading the functionality here and we could simplify by breaking them into two distinct scripts. I also believe this will simplify the switch syntaxes and overall logic to the assigner code, which will then get most/all of it's configuration from a yaml file.

[gdestuynder]

note that right now they're in separate functions and use separate classes, ie, all the non-config code is already separated, should we want to make them also separate files. both use the same bugzilla config though