Refactored Node3D rotation modes

* Made the Basis euler orders indexed via enum.
* Node3D has a new rotation_order property to choose Euler rotation order.
* Node3D has also a rotation_mode property to choose between Euler, Quaternion and Basis

Exposing these modes as well as the order makes Godot a lot friendlier for animators, which can choose the best way to interpolate rotations.
The new *Basis* mode makes the (exposed) transform property obsolete, so it was removed (can still be accessed by code of course).

modules/csg/csg_shape.cpp

@@ -576,6 +576,7 @@ void CSGShape3D::_validate_property(PropertyInfo &property) const {
 	} else if (is_collision_prefixed && !bool(get("use_collision"))) {
 		property.usage = PROPERTY_USAGE_NOEDITOR | PROPERTY_USAGE_INTERNAL;
 	}
+	GeometryInstance3D::_validate_property(property);
 }
 
 Array CSGShape3D::get_meshes() const {