Extract components to render custom image table actions

This way it'll be easier to refactor them. We're also giving a proper
title to the images index page.

app/components/admin/site_customization/images/table_actions_component.rb

@@ -0,0 +1,7 @@
+class Admin::SiteCustomization::Images::TableActionsComponent < ApplicationComponent
+  attr_reader :image
+
+  def initialize(image)
+    @image = image
+  end
+end