Remove old "default" layout without max-size support

[eddybrando]

Implementing the max-size layout in all pages will allow us to consolidate the default layout and DRY some code.

Currently we have two "default layouts". One with and one without the support for the max-size breakpoint. We should only have one default layout (the one that supports said breakpoint).

In order to remove the old default layout, we first need to complete these tasks:

• [x] #1873
• [ ] #1874