ewaol-config: Build Helper script

Introduced kas-ci-build.py wrapper script for building
ewaol images using kas, aiming to be used by the CI.

Building requires python3 and docker, and will pull the kas
docker container:
ghcr.io/siemens/kas/kas:latest

Issue-Id: SCM-2389
Signed-off-by: Nathan Dunne <Nathan.Dunne@arm.com>
Signed-off-by: Diego Sueiro <diego.sueiro@arm.com>
Change-Id: I2bd3b266e125c997963acec2df1eac844099a335