treewide: introduce osbase package and move things around

All except localregistry moved from metropolis/pkg to osbase,
localregistry moved to metropolis/test as its only used there anyway.

Change-Id: If1a4bf377364bef0ac23169e1b90379c71b06d72
Reviewed-on: https://review.monogon.dev/c/monogon/+/3079
Tested-by: Jenkins CI
Reviewed-by: Serge Bazanski <serge@monogon.tech>
diff --git a/metropolis/installer/test/main.go b/metropolis/installer/test/main.go
index b2fb8dc..f2c1f46 100644
--- a/metropolis/installer/test/main.go
+++ b/metropolis/installer/test/main.go
@@ -39,7 +39,7 @@
 
 	mctl "source.monogon.dev/metropolis/cli/metroctl/core"
 	"source.monogon.dev/metropolis/node/build/mkimage/osimage"
-	"source.monogon.dev/metropolis/pkg/cmd"
+	"source.monogon.dev/osbase/cmd"
 )
 
 // Each variable in this block points to either a test dependency or a side