[CC Number Validation Target] Network identifiers include (7d/9)

This patch removes the temporary "credit_card_network_identifiers.h"
include from the "credit_card.h" header (which does not need it) and
updates the files that were using credit card network identifiers (e.g.,
kVisaCard, kMasterCard) to include "credit_card_network_identifiers.h"
directly. In the few cases where the "credit_card.h" was included only
for the network identifiers, that include is removed.

Design doc: https://bit.ly/cc-number-validation-target-dd

Bug: b:281812289
Change-Id: I3ff883335cc2be5aad31fc54836d4709886c886b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5594452
Auto-Submit: Rouslan Solomakhin <rouslan@chromium.org>
Commit-Queue: Christoph Schwering <schwering@google.com>
Reviewed-by: Christoph Schwering <schwering@google.com>
Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Reviewed-by: Vidhan Jain <vidhanj@google.com>
Cr-Commit-Position: refs/heads/main@{#1311647}