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/node/core/cluster/BUILD.bazel b/metropolis/node/core/cluster/BUILD.bazel
index 4da6c76..665f94d 100644
--- a/metropolis/node/core/cluster/BUILD.bazel
+++ b/metropolis/node/core/cluster/BUILD.bazel
@@ -21,10 +21,10 @@
         "//metropolis/node/core/rpc",
         "//metropolis/node/core/rpc/resolver",
         "//metropolis/node/core/update",
-        "//metropolis/pkg/supervisor",
         "//metropolis/proto/api",
         "//metropolis/proto/common",
         "//metropolis/proto/private",
+        "//osbase/supervisor",
         "@com_github_cenkalti_backoff_v4//:backoff",
         "@org_golang_google_grpc//:go_default_library",
         "@org_golang_google_protobuf//proto",