[iOS][PageInfo] Add icons and open on tab for ATP

This CL adds both the left information icon and the right external arrow
icon to the AboutThisSite section of PageInfo. This CL also makes a
click on the ATP section open the diner url with more info about the
page.

Egtests that actually test the AboutThisSite section are going to be in
the internal repo (https://crrev.com/i/6955473).

Screenshot of PageInfo with the ATP section:
http://screen/7ErZMDibjyHESQy

Bug: 1512580, b:321267381
Change-Id: I9af403cbc95b7a5291467b2f3d604c87084cdee4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5272458


Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Filipa Senra <fsenra@google.com>
Reviewed-by: Ewann Pellé <ewannpv@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1261580}