Added statemachine deinit

[gamblor21]

For issue #4657

Two problems in deinit. First was the pin being used was not reset with reset_pin_number.

Second the deinit function was not calling common_hal_rp2pio_statemachine_deinit leaving the global pin usage out of sync with the pin now being reset.

Also noticed the constructor is not calling the common_hal version to construct a state machine but did not have time to fix that now. Did a small change so it doesn't allocate a state machine object to just copy to self->statemachine later.

[microdev1]

Thanks! for the PR @gamblor21.

I believe moving to the common_hal version of construct is a better option.
Also, I found the following while going through PulseIn.c.

• There is no error raised when all state machines are in use.
• Instead of using save_self, the struct can be passed as an arg to the interrupt handler.

The above are not necessary with respect to the current issue and can have their own PR.