CEL: Add bridge tech to relevant CEL records

Add the "bridge_technology" extra field key to BRIDGE_ENTER and
BRIDGE_EXIT CEL events to convey the bridge technology in use at the
time the record was generated.


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@417383 f38db490-d61c-443f-a65b-d21fe96a405b