Improve the UX of the similar pages page

[davidfischer]

• Add loading indicator
• I think favicons will work better than opengraph images. There's some risk but not much to loading favicons (mostly SVGs).
• Update the URL when the form is submitted
• Some error handling
• Currently the data is faked until the API is updated

[davidfischer]

Need to update the backend to parse the opengraph data, but that shouldn't be hard.

I think we can just grab the domain and append favicon.ico as a start. Favicons will probably be even better than opengraph data.

[ericholscher]

Ya, I meant description as well, but already solved that problem :)

[davidfischer]

I updated this to show the distance if it's available from the API. Let's merge this after the backend is deployed