res_pjsip_config_wizard: Add command to export primitive objects

A new command (pjsip export config_wizard primitives) has been added that
will export all the pjsip objects it created to the console or a file
suitable for reuse in a pjsip.conf file.

ASTERISK-24919 #close
Reported-by: Ray Crumrine

Change-Id: Ica2a5f494244b4f8345b0437b16d06aa0484452b