[iOS] Attach the translate client infobar to the active web state.

In order to display translation settings infobar in the Reading Mode
web state, use the infobar manager from the active web state which
currently supports the overlay queue infrastructure.

DanglingUntriaged-notes: Existing web state backed service
Bug: 444597320
Change-Id: I11e53ce092ab7ab5297fab78e3cf33a6119dfaef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6975977
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Nohemi Fernandez <fernandex@google.com>
Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Reviewed-by: Chris Lu <thegreenfrog@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1526268}