[iOS] Add support for escape/enter in the creation screen

Make sure that the TabGroup creation screen is compatible with usage
of the keyboard.

Fixed: 331762999
Change-Id: I858e9755e3d5962606aa89a624624f3acbe8d14b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5402881


Auto-Submit: Gauthier Ambard <gambard@chromium.org>
Reviewed-by: Ewann Pellé <ewannpv@chromium.org>
Commit-Queue: Ewann Pellé <ewannpv@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1280137}