AutofillWalletSyncBridge transfers IBANs into AutofillTable

This CL adds WalletMaskedIban as a new wallet type and update
`SetSyncData()` in AutofillWalletSyncBridge to transfer IBAN data to
AutofillTable.
This CL also adds `operator<<` to the IBAN class to support tests for
`AddChange` around << operator.

Bug: b:296651367
Change-Id: Id7c37777f1b10a9c17a90e269b7b5f120c3502dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4997278
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Florian Leimgruber <fleimgruber@google.com>
Reviewed-by: Olivia Saul <jsaul@google.com>
Commit-Queue: Qihui Zhao <qihuizhao@google.com>
Cr-Commit-Position: refs/heads/main@{#1224349}