enable actions on hand snap points

[DanielKinsman]

Handling pickables like two handed guns where you only want the "trigger" hand to fire it seems complex. I think it is simpler to add actions to the grab points instead of the pickable.

[DanielKinsman]

This is a quick fix which can perhaps be solved in a more holistic way, so happy to close it in favour of something more comprehensive. During the XR meeting someone mentioned just passing the controller events on down to the object directly, that would be nice. Perhaps something like a "pressed" event which tells the object:

• what input was pressed
• what controller pressed it
• where that controller is holding me