Make AFMMP open to extensions

[CaseyZS]

Is your feature request related to a problem? Please describe.
Issue #44 reminded me of something. Currently if someone wanted to add more functionality to the AFMMP right-click options, they'd need to modify the code that's already in place. In my experience (though I'd be happy to be proved wrong), creating new project providers creates a separate entry in the right-click menus. I'd like to see the ability for 3rd party add-ons to be nested under the same "Actor Framework" right click menu.

Describe the solution you'd like
Develop a plug-in architecture so that new AFMMP features could be added alongside the shipping code and menus dynamically updated in the AFMMP.

Describe alternatives you've considered
Brand new idea, so haven't had time to think of alternatives.

Additional context
I've admittedly spent close to 0 time thinking about whether or not this is technically feasible.

[niACS]

I have a customer making similar requests for custom plug-ins, so I'll be looking at some ideas. File this under "maybe someday."