Nav Unification: Check domain notices

[sixhours]

Steps to reproduce

• Starting at URL: /home/[your-site]/?flag=nav-unification
• On a site with an expired domain, you'll see something like this:

There are other non-JITM notices that pop up here that probably need testing. I usually trigger them by overriding the logic in that file manually; not sure if there's a better way.

[cpapazoglou]

@sixhours interesting enough, the text is overflowing in production already! It is just the fact that the overflowing content is hidden

and it is more prominent now due to the narrower sidebar.

Addressed here #46819. I would appreciate it if you could take a look!