[Enhancement] Add sorting, pagination, and new attributes to sources index table (#510)

* WIP - started improving handling of sorting for sources index table

* WIP - Added UI to table to indicate sort column and direction

* Refactored toggle liveview into a livecomponent

* Added sorting for all table attrs

* Added pagination to the sources table

* Added tests for updated liveviews and live components

* Add tests for new helper methods

* Added fancy new CSS to my sources table

* Added size to sources table

* Adds relative div to ensure that sorting arrow doesn't run away

* Fixed da tests

lib/pinchflat_web/helpers/sorting_helpers.ex

@@ -0,0 +1,20 @@
+defmodule PinchflatWeb.Helpers.SortingHelpers do
+  @moduledoc """
+  Methods for working with sorting, usually in the context of LiveViews or LiveComponents.
+
+  These methods are fairly simple, but they're commonly repeated across different Live entities
+  """
+
+  @doc """
+  Given the old sort attribute, the new sort attribute, and the old sort direction, returns the new sort direction.
+
+  Returns :asc | :desc
+  """
+  def get_sort_direction(old_sort_attr, new_sort_attr, old_sort_direction) do
+    case {new_sort_attr, old_sort_direction} do
+      {^old_sort_attr, :desc} -> :asc
+      {^old_sort_attr, _} -> :desc
+      _ -> :asc
+    end
+  end
+end