📦 NEW: CPrinter basis structure for compiling/testing/etc

Heavily inspired by the ScalaPrinter, I created a base structure for a CPrinter with the corresponding structure for transpilation, compilation and test execution, including a rt.c runtime library we probably will need to extend. There might be some leftovers from the ScalaPrinter we need to adapt...

Also I did not yet have the time to test this, but I'm pushing it here so you can take a look already and potentially base your work on it.