sockstat: support reporting of BBLog state

Add a -b option to print the BBLog state for TCP sockets.
Manually tweaked for stable/14.

Reviewed by: jtl, rrs
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D52944

(cherry picked from commit d801cc2d8542854a5dee9bfb25a15af6fa1dafad)