go: re-do the entire thing

This is a mega-change, but attempting to split this up further is
probably not worth the effort.

Summary:

1. Bump up bazel, rules_go, and others.
2. Switch to new go target naming (bye bye go_default_library)
3. Move go deps to go.mod/go.sum, use make gazelle generate from that
4. Bump up Python deps a bit

And also whatever was required to actually get things to work - loads of
small useless changes.

Tested to work on NixOS and Ubuntu 20.04:

   $ bazel build //...
   $ bazel test //...

Change-Id: I8364bdaa1406b9ae4d0385a6b607f3e7989f98a9
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1583
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/dc/topo/state/BUILD.bazel b/dc/topo/state/BUILD.bazel
index fefb3ef..6cb8d59 100644
--- a/dc/topo/state/BUILD.bazel
+++ b/dc/topo/state/BUILD.bazel
@@ -1,14 +1,14 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_library")
 
 go_library(
-    name = "go_default_library",
+    name = "state",
     srcs = ["state.go"],
     importpath = "code.hackerspace.pl/hscloud/dc/topo/state",
     visibility = ["//visibility:public"],
     deps = [
-        "//dc/proto:go_default_library",
-        "//dc/topo/proto:go_default_library",
-        "//go/pki:go_default_library",
+        "//dc/proto",
+        "//dc/topo/proto",
+        "//go/pki",
         "@org_golang_google_grpc//:go_default_library",
     ],
 )