New cleanup git-history based algorithm

[cleanup] Implement git history based cleanup
[cleanup] Git shallow clone validation
[cleanup] Syncing git branches and tags
Refine publish procedure: check already existing image by content signature
Rework publish procedure for cleanup
- Store metadata for images in the stages storage: map stages-signature by commit-id and image-name.
- Store project repository commit in the separate dedicated label: werf-project-repo-commit.
[publish-for-cleanup] Add image.WerfContentSignatureLabel=werf-content-signature label to all published images
Set content-signature for all stages into label

Other