webauthn: add UI sheets for hybrid feedback.

These UI surfaces are unreachable at the moment (outside of tests), but
serve to add (and test) Lottie animation support in WebAuthn code.

Do:

browser_tests --gtest_filter=BrowserUiTest.Invoke --test-launcher-interactive --ui=AuthenticatorDialogTest.InvokeUi_cable_v2_connecting

To see the animated illustration.

Change-Id: Ib0cb21d9917320d5dfaec9e43b160971359284f5
Bug: 1444776
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4549184


Reviewed-by: Nina Satragno <nsatragno@chromium.org>
Commit-Queue: Adam Langley <agl@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1148023}