[AR] Fluent interaction/multitouch not possible with the current design of Interactables

[hybridherbst]

At the core of the current design seems to be the assumption that objects need to be "selected first, then manipulated".

That's not necessarily desired behaviour, and there doesn't seem to be a way to configure this. Not even "dragging an object around" works without first selecting it.

To reproduce: build & run ARInteraction scene, create two cubes by tapping, try moving them around.
Expected: can move cubes around by directly dragging on them
Actual: can only move cubes around after first selecting them by single-tap. Directly dragging on a different cube than the selected one does nothing.

[sivatejachigicherla]

XRITK maps the manipulator to 3D object based on the selection.Manipulator can't be assigned to all objects at once so we need to select first and then manipulation can be done