Refactor micropub specific things out to a slice

slices/micropub/commands/posts/undelete.rb

@@ -0,0 +1,14 @@
+module Micropub
+  module Commands
+    module Posts
+      class Undelete < Adamantium::Command
+        include Deps["repos.post_repo"]
+        def call(params:)
+          slug = URI(params[:url]).path.split("/").last
+
+          post_repo.restore!(slug)
+        end
+      end
+    end
+  end
+end