Add music scales to C++ code

[Pocwiardo]

In Python code I used mingus library to check if given MIDI note belongs to given scale. We have to have this feature in C++ too. For given MIDI note value (integer) we have to check whether or not it belongs to given scale, for example "A Minor" (scale is a set of notes, which works as a pattern and repeats every octave, that is 12 MIDI values)

The task is to either:

• use Mingus library for C (there is some version of it out there, but it should be checked if it works and can be used)
• implement functionality from scratch

[Pocwiardo]

scale_notes vector of MIDI notes modulo 12 must now be obtained from the scale names