On Mac arm, the c api backing the python bindings does not propagate the
exceptions properly to the concretelang python module. This makes all
exceptions raised through `CompilerEngine.cpp` fall in the catch-all
case of the pybind exceptions handler.
Since there is no particular need for a public c api, we just remove it
from the bindings, and move all the content of `CompilerEngine.cpp`
directly in the `CompilerAPIModule.cpp` file.