[ios] add manual fallback credit card and address coordinator

And a common base class.

Bug: 845472
Change-Id: I12999d306804227e605e270c9b4f14bd8ee6a2bb
Reviewed-on: https://chromium-review.googlesource.com/c/1318914
Reviewed-by: Eric Noyau <noyau@chromium.org>
Commit-Queue: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606850}
9 files changed