[iOS][MF] Create Cells to show credentials

Adds cells to show credentials. These support dynamic fonts and have 2
buttons. One for password and one for username, which send the events
to the delegate passed when setting the cell up.

Mocks: https://folio.googleplex.com/ntp/Autofill/Autofill%20Manual%20Fallback

Bug: 845472
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ia375e00789fb21935817801b904ec7190a516875
Reviewed-on: https://chromium-review.googlesource.com/1183192
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585107}
4 files changed