To further mirror the file name and location requirements for php template
event listeners, require extension template event listener files to follow the
'<event name>_listener.html' naming format.
PHPBB3-11777
Per suggestion of EXreaction and nickvergessen, do not look for extension
template event listeners in styles/[style]/template/events/ but in
styles/[style]/template/event/ (without the trailing 's') to match the way
phpBB looks for php template event listeners.
PHPBB3-11777
The tests written for extension template events did not follow the convention
and documentation of placing template event files in the events/ subdirectory.
Moved the files to this subdirectory so the tests succeed again.
PHPBB3-11777
