Make FastNavPlugin ignore simple click input

[xeolabs]

Each time we click on the canvas without moving the mouse, FastNavPlugin will trigger a low-quality, high FPS render.

That results in an immediate low-quality render, which then fades into a high-quality image, each time we click. If we're just selecting an object, for example, we don't need that low/high quality fade effect each time.

Fix by making NavCubePlugin ignore clicks and taps.