feat(apds9960): Add gesture menu example with OLED and D-PAD.

[nedseb]

[nedseb]

How to test

This example uses multiple drivers. Build and flash the firmware so all drivers are available natively:

make firmware    # Build firmware with all drivers frozen
make deploy      # Flash to the board via OpenOCD

Then run the example:

make run SCRIPT=lib/<driver>/examples/<example>.py

Do not use mpremote mount for cross-sensor examples — it only mounts one directory and imports from other drivers will fail.