[ChromeCart] Use product image from ShoppingService for AddToCart

Currently we don't try to detect product image when AddToCart happens
due to technical limitations. Therefore, when an AddToCart is
detected, we show a fallback cart icon in ChromeCart, and the product
images won't be available until user visits the cart page which is a
suboptimal user experience.

This CL improves the situation by taking advantage of the product
images from ShoppingService. When an AddToCart is detected, we use
the PDP where AddToCart happens to query ShoppingService to see if
there are product image available. Two things worth mentioning about
this approach:
* This improvement depends on ShoppingService, so it won't be
  available for users who have ChromeCart but don't satisfy the
  requirement in ShoppingService.
* This CL only uses the cached product images in ShoppingService
  (i.e. using GetAvailableProductInfoForUrl API) instead of
  initiating backend fetch. This should be good enough because
  in most cases, the user needs to visit the PDP first before
  adding the product to cart, and the navigation should already
  bring the product image into cache.

Bug: 1407248
Change-Id: I1bf1ae566d7a3da5b99c31f6ad7df520baaca9ce
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4166473
Reviewed-by: Wei-Yin Chen <wychen@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Yue Zhang <yuezhanggg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1093921}