trigger: match irc op_public as publics

[dwfreed]

These are often called statusmsg or wallchops, and are often also used by channel modes that cause messages that would otherwise be blocked to be sent to chanops.

Adds a prefix filter to allow differentiating these from regular publics.

Also extends the debug output to include the trigger that tripped the debug

[dwfreed]

Last commit fixes an issue where the expands make it into the debug output unnecessarily