stepper auto-zero should allow reverse logic

[tigert]

Is your feature request related to a problem? Please describe.
When using auto-zero switch / optical sensor for stepper motor, optointerruptors are a common way to have optical limit switches, but there are two kinds, normally open (NO) and normally closed (NC). Especially optical interruptors use a phototransistor and can be either NPN or PNP type, which also has the same effect with reverse logic if you happen to have a NPN variant, so the circuit is disconnected when optical blockage is detected and not the other way around. Like if you connected the interruptor as a switch, you'd get a PRESS and RELEASE events swapped.

Describe the solution you'd like
It would be good to have an option to set the type of switch, whether it is a "close upon contact" or "open upon contact" type.

Describe alternatives you've considered
Thought of setting it in the stepper settings, but hardware is logically best set up in the device configuration.