[Help Wanted] More test modes

[jhoff]

The testAll method exists and is a useful way to test that the flaps are all working correctly, but it's not possible to enable it in the UI currently

There's also a testCount method that seems unreachable. I'm guessing that used to be tied to the count mode in the UI, which doesn't do anything.

I'm sure there are additional test modes that could be useful as well.

[shendriksza]

A test that verifies the hall effect sensor is working (and by extension the magnet polarity is correct) would be great