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/cloud/agent/main.go b/cloud/agent/main.go
index 45c3e52..511e688 100644
--- a/cloud/agent/main.go
+++ b/cloud/agent/main.go
@@ -8,9 +8,9 @@
 
 	"golang.org/x/sys/unix"
 
-	"source.monogon.dev/metropolis/pkg/bootparam"
-	"source.monogon.dev/metropolis/pkg/logtree"
-	"source.monogon.dev/metropolis/pkg/supervisor"
+	"source.monogon.dev/osbase/bootparam"
+	"source.monogon.dev/osbase/logtree"
+	"source.monogon.dev/osbase/supervisor"
 )
 
 var validTTYRegexp = regexp.MustCompile(`^[a-zA-Z0-9]+$`)