Added calculation for afferent coupling of types
Closes #671
I added a calculation for the type level afferent coupling metric based on @intjftw's solution in #711.
TODO:
- [ ] tests
@intjftw Since you have worked on efferent coupling in #711, I suggest you to review it, when this PR will be ready.
@kmkristof Since the development of this new metric was started after Implementation of C++ metrics parallelization (see #734) was merged, I suggest to implement this metric with multithread computation on the first attempt, based on the already implemented pattern.
We can consider this task as https://github.com/Ericsson/CodeCompass/labels/Level%3A%20Intermediate%20%283%29 with this added complexity.
Superseded by #780.