Reland "[Leipzig][Desktop] Settings: required field validation, backend part, 1/2."

This is a reland of commit 32b4a29a

Added a check for literals before using the field property, some details in the comment: https://chromium-review.googlesource.com/c/chromium/src/+/4234499/comments/be844dde_cec2d6fe

Original change's description:
> [Leipzig][Desktop] Settings: required field validation, backend part, 1/2.
>
> libaddressinput's AddressUiComponent was extended to store
> the required flag from the autofill's country data.
>
> Bug: 1408423
> Change-Id: I8db49c5af80ee9143ec57a8f8701ee1b777e00f0
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4218111


> Reviewed-by: Mohamed Amir Yosef <mamir@chromium.org>
> Reviewed-by: Stephen McGruer <smcgruer@chromium.org>
> Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
> Commit-Queue: Dmitry Vykochko <vykochko@google.com>
> Reviewed-by: Matthias Körber <koerber@google.com>
> Cr-Commit-Position: refs/heads/main@{#1102630}

Bug: 1408423
Change-Id: I8f50b99059f846ab5c24c025b0e576bc15991b3e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4234499


Reviewed-by: Matthias Körber <koerber@google.com>
Commit-Queue: Dmitry Vykochko <vykochko@google.com>
Reviewed-by: Stephen McGruer <smcgruer@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Mohamed Amir Yosef <mamir@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1103458}