test(sensors): Add mock encoder sensor
Add a new mock sensor driver for generating mock encoder sensor channel
data.
test(split): Add a peripheral sensor split test
Test BLE split logic for peripheral sensors (encoders).
* Enhance the BLE test runner to build additional peripheral builds
when detecting peripheral*.overlay files in the test.
* Add basic and multiple-peripheral tests to exercise the testing
support
* Add test for triggering local behaviors on split peripherals.
fix(ble): Fix building split code w/o settings
* Properly exclude storing peripheral addresses to settings when
settings support isn't turned on.