Add UX feedback for direct selection intersection

[dunity]

Tangible feedback should be given when a valid direct-selection intersection is detected. This will allow for far fewer false positive ray selects, when a direct select was intended.

• Add a single noticeable haptic pulse/tick when initially intersecting with an object
• Change object outline to an intermediate color (between ray hover, and selected colors). Ideally, rethink the highlight color temperature progression to more logically progress from deselected, to intersected, to selected (cold to hot perhaps).

[dunity]

I've posted a quick mock of such an approach in a new branch : improvements/dylanu/direct-select-feedback