UX improvements v1 (#39)

* Removed collection_type user input instead inferring from yt-dlp response

* Updated docs

* Added delete buttons for source; Refactored the way deletion methods work

* Update source to always run an initial index

* Added deletion to the last models

* Improved clarity around deletion operation

* Improved task fetching and deletion methods

* More tests

test/pinchflat_web/controllers/media_item_controller_test.exs

@@ -4,7 +4,6 @@ defmodule PinchflatWeb.MediaItemControllerTest do
   import Pinchflat.MediaFixtures
 
   alias Pinchflat.Repo
-  alias Pinchflat.Media
 
   describe "show media" do
     setup [:create_media_item]
@@ -19,10 +18,6 @@ defmodule PinchflatWeb.MediaItemControllerTest do
     setup do
       media_item = media_item_with_attachments()
 
-      on_exit(fn ->
-        Media.delete_attachments(media_item)
-      end)
-
       %{media_item: media_item}
     end