[IOS][Omnibox] Display the trend suggestions on the trend section

It seems that the trend suggestions doesn't have a unique suggestion
type. Which means we can't rely on the type of the suggestion to
identify which leading icon to display. Therefore we are relying on
the type and subtypes to identify the trending suggestion icons and to comply with other platforms.

Bug: None
Change-Id: I0d6514e9d4094844a2b38c605c1fb6d5b924e971
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4946690
Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Tomasz Wiszkowski <ender@google.com>
Commit-Queue: Ameur Hosni <ameurhosni@google.com>
Cr-Commit-Position: refs/heads/main@{#1212135}