Clean up error page layout

• 3f13645e: deduplicate default and no-footer layouts
  Abstracts the layout out into a reusable component that exposes a noFooter prop so that we don't need to repeat the same code in both layouts.
• 392ca815: consolidate error pages
  Refactors the error pages' code to be more reusable and less duplicated.

Closes #1454 (closed)