[ticket/11701] Loop variables are not passed correctly to events

PHPBB3-11701
[ticket/11701] Remove useless str_replace

PHPBB3-11701
[ticket/11701] Fix loops var check

PHPBB3-11701
[ticket/11701] Fix regex for appending |length

PHPBB3-11701
[ticket/11701] Refix regex for appending |length

PHPBB3-11701
[ticket/11701] Test events in loops

PHPBB3-11701
[ticket/11701] New line at EOF

PHPBB3-11701
[ticket/11751] Add mcp modules for softdelete  on update

PHPBB3-11751
Merge remote-tracking branch 'EXreaction/ticket/11701' into develop

* EXreaction/ticket/11701:
  [ticket/11701] New line at EOF
  [ticket/11701] Test events in loops
  [ticket/11701] Refix regex for appending |length
  [ticket/11701] Fix regex for appending |length
  [ticket/11701] Fix loops var check
  [ticket/11701] Remove useless str_replace
  [ticket/11701] Loop variables are not passed correctly to events
Merge pull request #1633 from nickvergessen/ticket/11751

[ticket/11751] Add mcp modules for softdelete  on update
[ticket/11777] Add subdirectory 'events/' to the template event search path

Makes the twig template engine look in the events/ subdirectory instead of the
main styles/[style]/template/ directory for extension template events. Note
that it does _not_ look recursively!

PHPBB3-11777
[ticket/11777] Move the testing template events to 'events/' subdirectories

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
[ticket/11777] Rename the extension template listener subdirectory to 'event/'

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
[ticket/11777] Require a suffix of '_listener' on extension template listeners

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
[ticket/11777] Fix new test for loop variables in extension template listeners

With the merge of https://github.com/phpbb/phpbb3/pull/1564 a new test has
been added. Renamed and moved the template listener file of that test to
comply with the new requirements.

PHPBB3-11777