[omnibox][search aggregator] Show content type icon in location bar

Updates OmniboxView to use the match icon URL for setting the omnibox
match icon. This allows for content type aggregator suggestions to
show the icon in the omnibox as well.

Note: Since the match icon relies on GetPopupRichSuggestionBitmap, the
icon is cleared whenever the popup is closed. As a result, the icon
will revert to the default globe icon when the popup is closed. Fixing
that behavior is low priority and is tracked in b:404335159.

Screenshot: https://screenshot.googleplex.com/7cSk4q8tdUDe635

Bug: 401229824
Change-Id: Ied8fbd22ab4be45c114f954ffe0be00106aa930a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6335491
Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Commit-Queue: Alex Chen <alexwchen@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1436938}