It now handles deinit, never_reset and sharing tracking. PWM
now runs in the WAIT state as well during a time.sleep().
_reset_ok() was removed because it was called in one spot right
before deinit().
Some PWMOut were also switched to a bitmap for use instead of
reference count. That way init and deinit are idempotent.
Fixes#6589. Fixes#4841. Fixes#4541.
Passing in a PWMOut still works but is deprecated. It will be
removed in CircuitPython 8.0.0
This also switches STM32 timer indices and channel indices to
0-based in our pin data rather than `- 1` everywhere. The latter is
more bug prone.
Most of the way for #3264
Tested on Metro M0, Metro M4, Feather S2, Feather nRF52840, Feather
STM32F4 and Arduino RP2040.