net80211: improve DDB output.

Start adding more fields to DDB output related to VHT (11ac) and
mark COM, VAP, and STA more explicitly to make show all vaps /..
more readable.

Sponsored by: The FreeBSD Foundaton
Reviewed by: adrian
Differential Revision: https://reviews.freebsd.org/D35977

(cherry picked from commit 5c9f992919eee6771dd15da278228e5f3bcee7b6)