Generic HCI Controller Support

[xudongzheng]

The TinyGo Bluetooth library currently includes support for HCI using an external ESP32 coprocessor running NINA-FW. Extending the library to support alternative controllers, in particular the Zephyr Bluetooth controller, would make it possible to use Bluetooth with a larger variety of chips/boards. The HCI protocol should be mostly compatible.

Zephyr's samples/bluetooth/hci_uart supports:

• Nordic nRF52
• Nordic nRF5340 Network Core
• ESP32/ESP32-C3/ESP32-S3

I've done some preliminary testing with RP2040 running TinyGo and Nordic nRF52840 running samples/bluetooth/hci_uart.

• Scanning
  • Mostly works
  • Some minor timing adjustments may be necessary to accommodate the speed of incoming scan data
• Connecting (as central) to peripheral works
• Notification subscription (as central)
  • Does not work with Nordic nRF52 HCI
  • Does work with ESP32-C3 HCI running the same Zephyr project