Split network_interfaces.h off of net_utils.h.

This includes the network interface enumeration functions, and wifi information that was previously lumped under net_utils.

BUG=488531
NOPRESUBMIT=true

Review URL: https://codereview.chromium.org/1154323007

Cr-Commit-Position: refs/heads/master@{#332644}
18 files changed