Fix erbui switch

[ohmtech-rdi]

This PR fixes multiple issues where the switch was returning the wrong position:

• The center position was not properly checked
• The positions in VCV Rack where inverted

When the control is not rotated, the top position is position first.

On the electronic side, Pin 1 happens to be at the bottom, and the switch inverts the position. So when in top position:

• Pin0 is 3V3 (_0 == 1)
• Pin1 is pulled down (_1 == 0) Which correct represents position_first.

However the VCV Rack button starts its first position at the bottom of the switch, which was just how the SVG images where ordered.

Note The Frohmager simulator will be updated in a later PR.

• [x] Check with Frohmager simulator
• [x] Check with Frohmager firmware
• [x] Check with Drop simulator (rotation)
• [x] Check with Drop firmware (rotation)