Extract feed routes (#2269)

* Extract feed routes from invidious.cr
* Removes the deprecated route for /feed/top
* Deprecate /view_all_playlist & use /feed/playlists
* Move feed views into their own directory

* Add haltf method to halt current route context
* Change status_code + return blocks to use haltf

* Set appropriate response headers for RSS routes

src/invidious/helpers/macros.cr

@@ -56,3 +56,12 @@ end
 macro rendered(filename)
   render "src/invidious/views/#{{{filename}}}.ecr"
 end
+
+# Similar to Kemals halt method but works in a
+# method.
+macro haltf(env, status_code = 200, response = "")
+  {{env}}.response.status_code = {{status_code}}
+  {{env}}.response.print {{response}}
+  {{env}}.response.close
+  return
+end