Makefile: implement "fully source containers" HMS-3883

[schuellerf]

Getting the stack up and running locally but all from source

also contains a followup of COMPOSER-2185 just to get it compiling

[schuellerf]

Note: unit tests fail due to inconsistencies with the images repo - "fixed" in
eef36f7
but the testframework apperently uses the old version of images

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[github-actions]

This PR was closed because it has been stalled for 30+7 days with no activity.

[bcl]

Hm, so just quickly trying make container_composer.dev here and this appears to assume things about my repo layouts -- it is trying to run make container.dev in ../osbuild which fails because I don't have the PR for osbuild checked out. I also don't really like the idea of one repo touching paths outside of it (whether or not it is dangerous in practice, it is unexpected).

[schuellerf]

The starting point of building the stack "fully from source" and the layout is described here
but you are right all layers already depending on outside source need this description too.
That's why I wanted/need to merge them in-order (as mentioned here )
so I'll revert this to draft and continue the process including the discussions in-order