Mouse support

[edumeneses]

Please merge after #2

[jcelerier]

The strategy we discussed with Olivier is:

• Use the Qt Quick 3D engine as much as possible for the 3D rendering in Domeport-Native as it gives us VR headset support and already comes with keyboard, mouse, gamepad & VR controls
• Take the blocks developed here and save them as part of the more general fulldome toolkit

[edumeneses]

This was done before our discussion.

I'll keep the mouse code as a possible process to be added to score-user-library.

We can still merge to document the process or, if @ogauthiersat already advanced past this point on the score, close this PR, and I'll manually add to the user library with another set of full-dome helper processes that convert input to Model Display coordinates (position/center).

What do you prefer?

[jcelerier]

I'll manually add to the user library with another set of full-dome helper processes that convert input to Model Display coordinates (position/center).

I think we could actually make a specific repo for this in the sat-mtl organization