Add class for adding build information to image

The image-ci-buildinfo class adds information about the ci build job into the image file. It is useful to uniquely identify images which were built in ci

Related to: https://git.kontron-electronics.de/sw/ked/plan/plan-yocto/-/issues/782 and https://git.kontron-electronics.de/sw/ked/plan/plan-yocto/-/issues/1214