Improve optics API

Basically this MR rework part of the optic to be provide an optic as a black box. This is mandatory to allow to provide widget on top of such device.

• Fix unit tests
• Cleaner inheritance from BaseOptic
• Features move_magnification (to use optics as an axis)
• Features available_magnifications (to provide generic information to the UI)
• Features state (mainly to catch MOVING state)
• Update triplemic optics to handle selection motor event