Add rotation sliders to armature widget

The rotation sliders allow the user to interact dynamically with the bones.
If the users selects another bone, the rotation returns to 0 and the
previously selected bone keeps the last transform applied to it.

See Issue #13980
Have double cone representation dependent on the vtkBoneWidget transform

This have the representation turn on itself when the bone is moving.

See issue #13980
Have cylinder representation dependent on the vtkBoneWidget transform

This makes the representation turn on itself when the bone is moving.

See issue #13980
Update rotation sliders from bone transform

The rotation sliders are updated directly from the bone transform,
allowing a finer control over the bone position.
Also, changing the bone node SetRoll method so it either simply set the
roll in rest mode or rotate the bone around itself in pose mode. This
allows to easily retrieve the Pose roll.

Finaly, changed bone widget ComputeRotationFromReferenceAxis() to be more
consistent.

See issue #13980