Replace the current BCT modules based on Octave/Matlab with BCT-py

For some time, BCT library has been translated into Python.

https://pypi.org/project/bctpy/

Check if the currently exposed BCT functions in TVB can be found in the python version also.
If so:

1. we should switch to use the BCT python implementation instead of the matlab based one.
2. all matlab wrapper code (calling matlab, checking the link, settings about matlab) can be removed from tvb-root.