net: ipv4: Implement IPv4 address conflict detection

Add support for IPv4 conflict detection, as specified in RFC 5227.
The new feature is optional and disabled by default.

Address conflict detection was implemented as a part of the IPv4
autoconf feature can be generalized to be available for all address
types.

Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
12 files changed