Tests

Add concept of state overlays #1973

Job	Run time
Build (Fedora)	1m 16s
Build (C9S)	1m 32s
build-integration	4m 16s
Code style	38s
Build - FCOS minimal	1m 42s
Debian Stable with sign-ed25519 and FUSE 2	8m 12s
Debian Stable with curl, sign-ed25519, no gpgme, FUSE 3	7m 6s
Debian Stable 32 bit	7m 55s
Debian Stable without libsystemd	7m 24s
Debian Testing	7m 40s
Debian Testing with libsoup3	7m 12s
Debian stable + static-prepareroot	7m 23s
Ubuntu Latest Release	7m 19s
Privileged testing	48s
	1h 10m 23s

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