Pages Error Route Module Rendering (#51374)
Continuing on changes to move the rendering logic into the bundles.
- Unifies edge render functions: `appRenderToHTML` and `pagesRenderToHTML` becomes `renderToHTML`
- When an error occurs, the error module's match is used so the module's internal render can be used (easing transition away from using the server's render method)
- Improved test resiliance
