[Enhancement] Allow redownloading of files for existing media items (#239)

* Added ability to specify overwrite behaviour when downloading media

* Added helper for redownloading media items

* renamed media redownload worker to disambiguate it from similarly named methods

* Added new redownload option to source actions dropdown

* Refactored MediaQuery to use a __using__ macro

* docs

lib/pinchflat/sources/sources.ex

@@ -4,12 +4,12 @@ defmodule Pinchflat.Sources do
   """
 
   import Ecto.Query, warn: false
-  alias Pinchflat.Repo
+  use Pinchflat.Media.MediaQuery
 
+  alias Pinchflat.Repo
   alias Pinchflat.Media
   alias Pinchflat.Tasks
   alias Pinchflat.Sources.Source
-  alias Pinchflat.Media.MediaQuery
   alias Pinchflat.Profiles.MediaProfile
   alias Pinchflat.YtDlp.MediaCollection
   alias Pinchflat.Metadata.SourceMetadata