Currently, it is necessary to manually specify version for all images in live_media, image_build and live_images. There is a single option global_version that can be used for this.

However, it's possible to get the version automatically in many cases.

For nightly composes (either Rawhide or Branched) without labels, we could just use release version as default.

When label is specified (for production composes), we should append the milestone from label to the version. There would need to be an exception for RC, as the last RC is going to be promoted to final.