Update and extend all integration tests such that they also
build outside of the Open Build Service. Along with the changes
on the descriptions a simple build-tests.sh script was added
to drive the build process. The build is based on the kiwi
boxbuild plugin in container mode to build the tests
from a given build-tests directory. A new chapter to document
how to Build the Build Tests is also provided and referenced
on the github main page.
