tests hardware: Add machine_Counter.py.

This adds a hardware test for `machine.Counter`. It requires two jumper
wires between two pairs of pins, uses `machine.Pin` and `machine.PWM` to
generate pulses and control the `direction` of counting, and `machine.Counter`
to input on two of them.

Currently supported on:
- esp32 (tested on ESP32 board)
- mimxrt ???
- esp8266 ???
- rp2 ???
- samd21 ???

Signed-off-by: IhorNehrutsa <[email protected]>

Author: IhorNehrutsa