types: Add types for IPs and MACs in byte form
types: Add types for IPs and MACs in byte form

This will be used by future code, mainly for storing data retrieved over
netlink in a typesafe way.

Change-Id: I663e7cdf5876397426338f6a733aa6a7dd8fca95
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/phosphor-networkd,openbmc/phosphor-networkd