WebUI: CrOS Settings: consent page tests

This CL connects the new consent page to the esim flow ui. The new
consent page waits to scan until after the user has consented by
hitting the `scan` button. Tests are also added accordingly.

screenshot: https://screenshot.googleplex.com/coQY5wUEqa5LNiz

Bug: b/290786735
Test: browser_tests, manual verification completed
Change-Id: I7ab9eb0d90143c127ca458c3c3f07fd5a496b165
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4766937


Reviewed-by: Chad Duffin <chadduffin@chromium.org>
Commit-Queue: Michael Rygiel <michaelrygiel@google.com>
Cr-Commit-Position: refs/heads/main@{#1184814}