[Discounts] Add discounts bubble view

This cl does the following:
  * Adds DiscountsBubbleDialogView, it can be shown automatically
    after the DiscountsIconView has finished expanded if
    CommerceUiTabHelper says it should be shown automatically,
    otherwise it shows when the user clicks the DiscountsIconView.
  * Records relevant metrics (histogram, user action, and UKM).

Note: This is a part of a refactoring work. The following files are
copied from the existing code, we will follow up to clean up the old
code in another cl.
  * c/b/ui/views/commerce/discount_bubble_dialog_view is from
    c/b/ui/views/autofill/payments/offer_notification_bubble_views
  * c/b/ui/views/commerce/discounts_coupon_code_label_view from
    c/b/ui/views/autofill/payments/promo_code_label_view

Bug: 351935350
Change-Id: I75ec4377ff089a53f29e5de06351c9c67aa23d8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5693032
Commit-Queue: Mei Liang <meiliang@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1328932}