When using the kas menu command, we need to track the repository
location outside of the kas container as well. This is required to
prepare the environment for a later kas-container build, as the repo
path inside the container is different from the outside one. For that,
the location of KAS_REPO_DIR is passed via an env-var into the container.
There, this value is picked up by the menu plugin and written to the
.config.yaml file as `_source_host_dir`. When running kas-container build,
we check if the .config.yaml file contains this node and set the
KAS_REPO_DIR accordingly. The schema is extended accordingly.
Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
[Jan: rework _source_dir_host extraction to make it usable for menu as well]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>