Revise network info to indicate IP addresses per NIC

Small changes to what_pi that make it easier to see which NIC is associated with each IP address. I tested on a variety of Pi models, with output from my runs shown below. I verified a 4GB Pi 4B that you might not have already tested. I configure each Pi, except "buster4", with minimal GPU memory and with the "lite" version of Raspian (no X-windows). I think this is why my video codecs typically all are disabled.

Attached file shows results of tests that were run. testing-what_pi.txt