luci-mod-admin-full: improve interface overview display

Remove the guessing of primary interfaces for now as we cannot yet properly
track parent / child interface relations.

Instead, add tooltips to the interface icons displaying detailed physical
layer information per netdev.

For dynamic or true alias interfaces (using "@" notation), skip the
reporting of MAC and traffic stats.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>