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/go/net/tinylb/tinylb.go b/go/net/tinylb/tinylb.go
index 67a639e..439628e 100644
--- a/go/net/tinylb/tinylb.go
+++ b/go/net/tinylb/tinylb.go
@@ -16,8 +16,8 @@
 	"sync"
 
 	"source.monogon.dev/go/types/mapsets"
-	"source.monogon.dev/metropolis/pkg/event"
-	"source.monogon.dev/metropolis/pkg/supervisor"
+	"source.monogon.dev/osbase/event"
+	"source.monogon.dev/osbase/supervisor"
 )
 
 // Backend is to be implemented by different kinds of loadbalancing backends, eg.