Fix legacy support issues and 404 page

[Iheuzio]

Issues

404 Page

• 404 page is tracked by the entire website when we can just use a fallback
• 404 page does not have a navbar for the other menus, just a back button
• CSS is not positioned correctly, so content is not centered properly

Internet explorer support

• There are some tags that could break support on older browsers entering the client, resolved many of the issues with the selectors

Express

• Revalidation for caching

HTML

• Add in missing header information

Images

• Images were all draggable, causing an issue on certain pages, such as 404
  

Things to Note

• Posters use medium format, causing CRP and DOM issues when constructing certain pages (discovery and main). Trying to solve it when tracking onLoad with one of previous commits works to render everything without the images, which speeds up constructing the DOM for the discovery page greatly. However, I ran into issues on the Main page, so there's a possible solution in there.

[Iheuzio]

The commit for the onLoad was 9d9053b