streamline bpftool net dump

[borkmann]

Few minor improvements to keep tracking:

For human readable output dump "prog id %u" for progs and "link id %u" for links consistently. Currently some types dump just "id %u" and other use "prog_id %u" ("_").

The Documentation/bpftool-net.rst is in some cases overly specific in which order what is dumped (is it relevant for man page?) and examples could need a refresher.

[qmonnet]

is it relevant for man page?

No, this should probably be removed at some point.

I'm tagging with documentation, with the understanding there's also changes required in the code. Thanks for filing this!