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.
It doesn't need never reset because the status LED is only active
when user code isn't.
This also fixes PWM never reset on espressif so that deinit will
undo it.
Fixes#6223
