[Housekeeping] Store the upload event as a datetime rather than a date (#269)

* [WIP] renamed and migrated upload_date column

* Refactored yt-dlp media module

* Refactored parse_upload_date

* Refactored media item upload_date_index

* Got media tests running

* Refactored media item table live

* Cleaned up the stragglers

* Fixed old oversight re: original_url

test/support/fixtures/media_fixtures.ex

@@ -23,7 +23,7 @@ defmodule Pinchflat.MediaFixtures do
         short_form_content: false,
         media_filepath: "/video/#{Faker.File.file_name(:video)}",
         source_id: SourcesFixtures.source_fixture().id,
-        upload_date: DateTime.utc_now()
+        uploaded_at: DateTime.utc_now()
       })
       |> Pinchflat.Media.create_media_item()
 
@@ -97,7 +97,8 @@ defmodule Pinchflat.MediaFixtures do
       description: "desc1",
       aspect_ratio: 1.67,
       duration: 123.45,
-      upload_date: "20210101"
+      upload_date: "20210101",
+      timestamp: 1_600_000_000
     }
 
     Phoenix.json_library().encode!(media_attributes)