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/test/swtpm/swtpm_cert/main.go b/metropolis/test/swtpm/swtpm_cert/main.go
index 7b14f3a..8d5663b 100644
--- a/metropolis/test/swtpm/swtpm_cert/main.go
+++ b/metropolis/test/swtpm/swtpm_cert/main.go
@@ -24,7 +24,7 @@
 
 	"github.com/spf13/pflag"
 
-	"source.monogon.dev/metropolis/pkg/pki"
+	"source.monogon.dev/osbase/pki"
 )
 
 func getSignkey() *rsa.PrivateKey {