drivers: cc2d23s temp/humidity sensor implementation

[bpbradley]

Closes #2

Also adds a structure for implementing out of tree drivers and tests.

To do before merge:

• [x] Add structure for out of tree drivers
• [x] Add structure for out of tree tests
• [x] Include cc2d23s driver in zephyr tree
• [x] Implement driver API
• [x] Integrate driver in main application code
• [x] Write functional unit tests
• [x] Add unit tests to github actions
• [x] Test integration on nrf52840dk

[bpbradley]

Driver is implemented, I will need to order samples to properly test them and verify the data is correct though.

Edit: Just ordered a few of these for testing with. https://www.digikey.com/en/products/detail/CC2D23-SIP/235-1359-ND/4732675?itemSeq=377568404

Should be able to test early to mid next week.

[bpbradley]

Unit tests written and passing, but not targeting hardware yet until I get sensors in. Github actions are now running tests on every push.

All that's needed is to test on hardware and then it is ready to merge.

I think I have some formatting issues that need to be addressed as well.

[bpbradley]

Had to fix a few small things, but this appears to be functional and all tests are passing on my setup on hardware. Getting accurate temperature and humidity data as well.

I believe we are good to merge.

[bpbradley]

Some considerations for future improvements:

1. This isn't calculating fractional sensor data as it isn't necessary for our application. If we ever plan to upstream this sensor to zephyr, we should implement that.
2. There are a number of functions on the sensor not currently implemented in this driver as they aren't necessary for us. Again, we should implement these if we plan to upstream. I did implement a couple of them at first, but decided to pull them out as they weren't used.

[krook]

Excellent, nice work @bpbradley