[iOS] Add search tabs shortcut from tab grid

See video:
https://drive.google.com/file/d/1zGHB3jSKW4MCDs3hQB3R2hCCWilDCknM/view?usp=share_link

Fixed: 1384656
Change-Id: I27a76284cacf271adee2a6b76b8e2e05b88ca617
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4026923


Reviewed-by: Ali Juma <ajuma@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Aliona Dangla <alionadangla@chromium.org>
Reviewed-by: Louis Romero <lpromero@google.com>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1075568}