[Enhancement] Add media count to sources page (#251)

* [WIP] Got query kinda working, now to refactor other queries

* Refactored all query methods to use dynamic snippets

* Refactored tab layout to grab tabs by name

* Removed standalone show buttons from in-app tables

* Removed unneeded comment

lib/pinchflat/sources/sources.ex

@@ -127,7 +127,7 @@ defmodule Pinchflat.Sources do
     Tasks.delete_tasks_for(source)
 
     MediaQuery.new()
-    |> MediaQuery.for_source(source)
+    |> where(^MediaQuery.for_source(source))
     |> Repo.all()
     |> Enum.each(fn media_item ->
       Media.delete_media_item(media_item, delete_files: delete_files)