refactor(users/Profpatsch/whatcd-resolver): init MyLabel

move the label stuff into its own temporary module (until we figure
out what to put into pa-label).

Also rewrite a few things to use t2/t3.

Change-Id: I8cc8678ec01a56d6c738eb4833a3ba566a7a1e20
Reviewed-on: https://cl.tvl.fyi/c/depot/+/13242
Tested-by: BuildkiteCI
Reviewed-by: Profpatsch <mail@profpatsch.de>

users/Profpatsch/whatcd-resolver/default.nix

@@ -13,6 +13,7 @@ let
       ./src/WhatcdResolver.hs
       ./src/AppT.hs
       ./src/Bencode.hs
+      ./src/MyLabel.hs
       ./src/JsonLd.hs
       ./src/Optional.hs
       ./src/Html.hs