Build AlmanacNetwork

Summary: Ref T5833. This differentiates address spaces like the public internet from VPNs, so when a service is available at 192.168.0.1, we'll know it's on some specific NAT block or whatever.

Test Plan: See screenshots.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T5833

Differential Revision: https://secure.phabricator.com/D10715