Make a global `ICommBoundary` variable for communication

In hindsight, I think it's best to prioritize the convenience of easy telemetry over cleanly modular design.

The core issue is that I think telemetry should be just as easy as printing to std::cout, just include and you can write your call. Currently, we have to pass a ICommBoundary through constructors, not ideal and requires non trivial refactoring and work.

I was thinking of making a basic interface like bind_comm_object() to set the global var, and for now get_comm_object() to get it. Later on I want to move to even more ergonomic interfaces for text logging and formatting.

If you want to try this issue, talk to me first. I'm not convinced this is a 100% good idea so I want to hear your opinion.