Start integrating playlist support (#13)

* [WIP] updated the output of VideoCollection to include playlists

* Updated source's name to collection_name; supported playlist ID/name fetching

* Hooked up collection_type to form; refactored enqueue_pending_media_downloads

* Added friendly_name to form

* Added media profile link to source view

* Updates comment

lib/pinchflat_web/controllers/media_sources/source_html.ex

@@ -24,4 +24,11 @@ defmodule PinchflatWeb.MediaSources.SourceHTML do
       {"Monthly", 30 * 24 * 60}
     ]
   end
+
+  def friendly_collection_types do
+    [
+      {"Channel", "channel"},
+      {"Playlist", "playlist"}
+    ]
+  end
 end