Implement GetNetworkList on Mac/iOS to expose IPv6 address attributes.

Enhance attributes mapping to expose IPv6 temporary and deprecated address attributes on Mac. For iOS, it should only be a non-functional refactor change.

Also refactor the code to facilitate testing and add additional testing.

BUG=413437

Review URL: https://codereview.chromium.org/715513005

Cr-Commit-Position: refs/heads/master@{#304231}
10 files changed