[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

lib/pinchflat/utils/datetime_utils.ex

@@ -1,17 +0,0 @@
-defmodule Pinchflat.Utils.DatetimeUtils do
-  @moduledoc """
-  Utility methods for working with dates and datetimes
-  """
-
-  @doc """
-  Converts a Date to a DateTime
-
-  Returns %DateTime{}
-  """
-  def date_to_datetime(date) do
-    date
-    |> Date.to_gregorian_days()
-    |> Kernel.*(86_400)
-    |> DateTime.from_gregorian_seconds()
-  end
-end