New pin mapping helper

[Paciente8159]

New pin mapping helper that allow an easier pin mapping definition/setup for boardmaps.

To define a pin on a board you needed to define the bit and port of the pin like this

#define STEP0_BIT 2	 // assigns STEP0 pin
#define STEP0_PORT D // assigns STEP0 port

This now can also be done like this

#define STEP0_PIN D2 // assigns STEP0 pin

On MCU's like the ESP32 and the RP2040 this can be done like this

#define STEP0_PIN GPIO3 // assigns STEP0 pin

The new pin mapping helper will generate under the hood the BIT and PORT definitions.
To prevent configuration errors, if the pin was already defined via BIT and PORT, that will take precedence over the new PIN definition and the PIN definition will have no effect.