Pad Revamped Omnibox Actions for more vertical space.

Suggestions with attached actions are presented "closer together"
to indicate that omnibox actions are related to the suggestion
directly above.

Revamped UI groups all visual elements together, relaxing the need for
denser packing of the suggestion components.

Bug: 1418077
Change-Id: Ia32235e0c0900ff5d0c45bdc4f01c155f60ef370
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4686072


Reviewed-by: Fred Mello <fredmello@chromium.org>
Code-Coverage: Findit <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: Fred Mello <fredmello@chromium.org>
Auto-Submit: Tomasz Wiszkowski <ender@google.com>
Cr-Commit-Position: refs/heads/main@{#1170476}