Rename Quaternion.setEulerAnglesDegXYZ to .rotateEulerAnglesXYZ
Rename Quaternion.setEulerAnglesDegXYZ to .rotateEulerAnglesXYZ

This is a generalization like for the other rotate* methods which will
apply the rotation. Also, it seemed that the original method was wrong
and gave incorrect results.
Also add Quaternion.getEulerAnglesXYZ() which will convert a quaternion
back to euler angles in XYZ rotation order.
JOML-CI/JOML,JOML-CI/JOML,JOML-CI/JOML,FortressBuilder/JOML,FortressBuilder/JOML,roquendm/JOML,roquendm/JOML