[ticket/12328] Add Template Event index_body_stat_blocks_after

PHPBB3-12328
[ticket/12328] Change "since" to B3

PHPBB3-12328
Merge remote-tracking branch 'paybas/ticket/12328' into develop-ascraeus

* paybas/ticket/12328:
  [ticket/12328] Change "since" to B3
  [ticket/12328] Add Template Event index_body_stat_blocks_after