Joint entities rotations

[exoexo-dev]

trafficstars

Objective

• Allow to set the local rotation of the connected entities in RevoluteJoint (in 3D only) and in SphericalJoint

Solution

• The rotation of the entities is controlled by the joints, which forces you to nest the connected entities inside another transform in order to change their rotation relative to the joints axes
• This PR adds local_rotation1 and local_rotation2 (analogous to local_anchors) that are being added to the rotations synced from the entities transforms
• These fields allow to set additional rotations of the entities relative to the joints axes