Clone Prusa Mk3 LCD cover, knob and supports

Modifications:

Cover:
- replaced text from Original to Clone

Knob:
- can also be used with longer shaft (if necessary)

Support left:
- thicker holes for screws (2.4mm)

Support right:
- holes were moved to the inner side
- cut to larger contrast potentiometer
- thicker holes for screws (2.4mm)

The original part can be found here:

- https://github.com/prusa3d/Original-Prusa-i3/blob/MK3/Printed-Parts/stl/LCD-cover-ORIGINAL-MK3.stl
- https://github.com/prusa3d/Original-Prusa-i3/blob/MK3/Print