[Enhancement] Add pagination for a source's media (#190)

* [WIP] added first attempt at pagination component

* Hooked up pagination for downloaded media

lib/pinchflat/utils/number_utils.ex

@@ -0,0 +1,16 @@
+defmodule Pinchflat.Utils.NumberUtils do
+  @moduledoc """
+  Utility methods for working with numbers
+  """
+
+  @doc """
+  Clamps a number between a minimum and maximum value
+
+  Returns integer() | float()
+  """
+  def clamp(num, minimum, maximum) do
+    num
+    |> max(minimum)
+    |> min(maximum)
+  end
+end