Rebase over `ping-cpp`

[ES-Alexander]

This library has significant overlap with our existing ping-cpp repo. It would be best if we can avoid the redundant code writing and double-tracking of problems by making this library inherit from/depend on ping-cpp. This has been the plan for a while, but making an issue to formally track it.

The Arduino library-registry doesn't support submodules, so the best approach (to me) seems to be making ping-cpp's deployment branch into its own Arduino library (e.g. bluerobotics-ping-cpp), and then using the depends tag in library.properties of ping-arduino so it auto-installs bluerobotics-ping-cpp. Would require making tags of ping-cpp's deployment, but that shouldn't be too much overhead.

From what I can tell of the ping-cpp source, an implementation would require creating

• hal/time/arduino/ping-time.cpp with a class PingTime per the spec
• hal/link/arduino/ping-port.cpp with a class PingPort per the spec
• library.properties in ping-cpp's deployment branch, per the Arduino spec
• revised/corrected examples in this repo to make use of the slightly different #includes and naming

I'm unsure whether it's possible to ignore certain files in Arduino library compilation, but if not we may need to make a duplicate deployment branch specifically for Arduino, without the desktop components (and possibly without the CMakeLists.txt files).

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An alternative approach would be to use git subtree, in which case the same files still need to be created, but the Arduino component could be managed directly in ping-arduino instead of in ping-cpp, and only one library would be required. That simplifies the initial setup at the cost of getting updates from and pushing updates to ping-cpp becoming messier and more complicated. I expect the wrapper and base library approach described above would be cleaner and easier to maintain long term.

[ES-Alexander]

May be worth waiting until these are merged:

• Include hal directory, add check for generated headers ping-cpp#39
• Fix yeild typo (yeild -> yield) ping-cpp#43
• src: device: ping-device.cpp: add auto-baud support ping-cpp#44

and may be worth doing #34 at the same time as the transfer.