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).
docs: Fix incorrect kconfig default values
fix(Kconfig): Added a name to EC11's trigger mode choice, allowing it to be set in device Kconfig.defconfig
refactor(Kconfig): Moved designer defaults out into new files
