[STAPLE/Pelvis + Femur] new methods by RWTHmediTEC could be added

[modenaxe]

These methods recently published by RWTHmediTEC would be nice to add:

• https://github.com/RWTHmediTEC/PelvicLandmarkIdentification
• https://github.com/RWTHmediTEC/PelvicLandmarkIdentification_Subburaj
• https://github.com/RWTHmediTEC/FemoralCoordinateSystem

femur paper: https://www.nature.com/articles/s41598-020-77479-z

[MCM-Fischer]

Pelvis algorithm was added in #118.