vfd: extend vfd_setState function with direction enum (default fwd)
main: reduce log output from buzzer task
config: use mos1 as vfd_FWD output
control:
add MANUAL state: motor can be controlled via preset buttons
adjust code slightly to support new state (also see updated
function-diagram)
Add vfd.cpp/hpp with functions to control the VFD via 4 digital pins
Add way to test the vfd via SET button (rotate speed level) and START
button (toggle motor on/off)
