Add delegate to editor menu promo card view to handle button presses.

Add EditorMenuControllerImpl as a delegate of EditorMenuPromoCardView
to handle button presses. Buttons still don't do anything, will add
proper functionality in a followup once EditorMediator APIs are ready.

Bug: b:295061567
Change-Id: I0afdb6345baac40b3bda19f92e704b5b536ae100
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4812842
Reviewed-by: Tao Wu <wutao@chromium.org>
Commit-Queue: Michelle Chen <michellegc@google.com>
Cr-Commit-Position: refs/heads/main@{#1188845}