Updates for user testing

[JamesProvan-UL]

Some new features and config options to aid with user testing.

• Hold fist to recenter mouse cursor.
• Added pinch and scroll thresholds to config.
• Adding interaction bounds to config - prevent mouse movement if outside, can be toggled on/off in config.
• Absolute mouse position control - toggled via config (uses new interaction bounds).
• Adding new cursor deadzone that activates when pinch / right-click gesture is detected. Move 3cm to break the deadzone lock.

[2birds]

Thanks Jim 👍