lxd/util/net: Adds CanonicalNetworkAddressFromAddressAndPort function
lxd/util/net: Adds CanonicalNetworkAddressFromAddressAndPort function

To make explicit that we accept partial addresses with just the host part, such as "[::]".

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

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