refactor iqdb endpoints

app/logical/iqdb_proxy.rb

@@ -0,0 +1,18 @@
+class IqdbProxy
+  def self.query(url)
+    raise NotImplementedError unless Danbooru.config.iqdbs_server.present?
+
+    url = URI.parse(Danbooru.config.iqdbs_server)
+    url.path = "/similar"
+    url.query = {url: url}.to_query
+    json = HTTParty.get(url.to_s, Danbooru.config.httparty_options).parsed_response
+    decorate_posts(json)
+  end
+
+  def self.decorate_posts(json)
+    json.map do |x|
+      x["post"] = Post.find(x["id"])
+      x
+    end
+  end
+end