Module and Processor Registry

[tomeichlersmith]

Currently, ldmx-app requires that we list the libraries that are needed to use the processors we wish to run. Constructing a registry automatically during the configuration (cmake) or build (make) steps would help us transition ldmx-app to allow for each processor class to automatically load any libraries that it depends on.

Goals:

• Automatically list any and all processors in a registry that can be read by ldmx-app at or before runtime.
• Allow a user to include processors written outside of ldmx-sw (like in the ldmx-analysis repo)
• Remove need to specify library dependencies of the processors, but also keep dynamic loading of libraries to keep ldmx-app independent of processor libraries and light.

[tomeichlersmith]

I have integrated a solution that is different that what I intended with this issue but reaches the same goals. Essentially, each processor is required to have a mirror python configuration class that defines the parameters for the C++ processsor. In this python class definition, we can include the libraries that are necessary for the class to function. In this way, the libraries for the processor are automatically given to the ldmx application and then loaded.