OneWire not working on ESP32-S2

[dhalbert]

User here noticed that OneWire is not working on ESP32-S2: https://forums.adafruit.com/viewtopic.php?f=19&t=187286

Two problems:

1. Open drain outputs not working: Open Drain outputs don't work (also breaks bitbangio.I2C) #3845. I have a simple fix for this.
2. Onewire times seem to be somewhat too long. Still researching that.

[dhalbert]

There are various Onewire implementations for Espressif chips.
This one uses delays, and is similar to what we do, including using the same ldeay mechanism:
https://github.com/UncleRus/esp-idf-lib/blob/master/components/onewire/onewire.c

This one uses RMT. The README says the original implementation used bitbanging and delays, but it was too unreliable:
https://github.com/DavidAntliff/esp32-owb

Another RMT implementation:
https://github.com/mongoose-os-libs/onewire-rmt

RMT is a better idea.

[dhalbert]

We think we'll turn off OneWire on ESP for now and move to long-term.

[dhalbert]

Also see #3822 for a specific example.