feat: Implement the front panel I/O behavior and motor driver handling as specified in the ZMX Crate manual
- Inputs signals from DIP-switches, pushbuttons, and rotary switch on front panel are read from parallel-to-serial chip (SN74HC165).
- End switch configuration from the front panel is taken into account to generate uniform CW/CCW end switch signals.
- Behavior for /Enable Limit Switches input of back panel implemented.
- Power up, disconnect, and reset behavior for motor driver implemented.
- fix: Behavior for motor power stage deactivation corrected.
- Dimming of front panel LEDs through rotary switch implemented.
- Status signals for front panel LEDs are written to serial-to-parallel chip (SN74HC595).
- Implemented automated testbenchs for leaf-level design units.