[Autofills in Devtools] Emit devtools issues when labels have neither for attribute nor nested input.

Bug: 1399414
Change-Id: Iceedd5aba99ef4bf84275d43294d0436618e95c4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4181037
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Wolfgang Beyer <wolfi@chromium.org>
Auto-Submit: Bruno Braga <brunobraga@google.com>
Reviewed-by: Florian Leimgruber <fleimgruber@google.com>
Reviewed-by: Alex Rudenko <alexrudenko@chromium.org>
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1099754}