[packaging] import mer packaging adapted to optional X11 and subtree builds
remove common submodule from subtree
Squashed 'gst-plugins-base/common/' content from commit cb5da59

git-subtree-dir: gst-plugins-base/common
git-subtree-split: cb5da59f450f0cea9a360bd95e6295cb53f28e09
Merge commit 'bafb74b5861da5c26e5458809a92d316352bae4b' as 'gst-plugins-base/common'