sources: don't escape Unicode characters in tag search URLs.

Fix it so that Unicode characters aren't unnecessarily percent-encoded when generating tag search
URLs. For example, generate URLs like this:

* https://www.pixiv.net/tags/オリジナル/artworks

Not like this:

* https://www.pixiv.net/tags/%E3%82%AA%E3%83%AA%E3%82%B8%E3%83%8A%E3%83%AB/artworks

app/logical/source/extractor/hentai_foundry.rb

@@ -39,7 +39,7 @@ module Source
         tags = page&.search(".boxbody [rel='tag']").to_a.map(&:text)
 
         tags.map do |tag|
-          [tag, "https://www.hentai-foundry.com/pictures/tagged/#{CGI.escape(tag)}"]
+          [tag, "https://www.hentai-foundry.com/pictures/tagged/#{Danbooru::URL.escape(tag)}"]
         end
       end