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

test/support/fixtures/media_source_fixtures.ex

@@ -16,9 +16,10 @@ defmodule Pinchflat.MediaSourceFixtures do
       %Source{}
       |> Source.changeset(
         Enum.into(attrs, %{
-          name: "Source ##{:rand.uniform(1_000_000)}",
+          collection_name: "Source ##{:rand.uniform(1_000_000)}",
           collection_id: Base.encode16(:crypto.hash(:md5, "#{:rand.uniform(1_000_000)}")),
           collection_type: "channel",
+          friendly_name: "Cool and good internal name!",
           original_url: "https://www.youtube.com/channel/#{Faker.String.base64(12)}",
           media_profile_id: ProfilesFixtures.media_profile_fixture().id,
           index_frequency_minutes: 60