res_pjsip_logger: Expand functionality to improve logging.

The PJSIP packet logger now has the following CLI commands:

pjsip set logger pcap <filename>

When used this will create a pcap file containing the incoming
and outgoing SIP packets, in unencrypted form.

pjsip set logger verbose <on / off>

This allows you to toggle logging to verbose on and off.

pjsip set logger host <IP/subnet mask> add

This allows you to add an additional IP address or subnet
mask to logging, allowing you to log multiple instead of
just a single IP address or all traffic.

The normal "pjsip set logger host" CLI command has also been
expanded to allow subnet masks as well.

ASTERISK-28895

Change-Id: If5859161a72b0d7dd2d1f92d45bed88e0cd07d0e