scripts: extend west build command to support sysbuild CMake project
scripts: extend west build command to support sysbuild CMake project

west build now support the sysbuild CMake project which allows users
to easily enable and build a bootloader together with any sample.

This will allow for cleaning up samples and boards which already does
custom multi image in a non-generic way, for example:
- mps2_an521 which includes a build for remote board
- samples/ipc/ which includes a samples for remote board
- esp32 which includes custom bootloaders

Signed-off-by: Torsten Rasmussen <a7c5b1d5a1f41fce6edfa3f7c2392ae0c59deafe@nordicsemi.no>

galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr