message: Emit irreverisble_block signal on replay
diff: @@ -895,6 +895,9 @@ struct controller_impl {
  bool trust = !conf.force_all_checks && (s == controller::block_status::irreversible || s == controller::block_status::validated);
  auto new_header_state = fork_db.add( b, trust );
  emit( self.accepted_block_header, new_header_state );
  + // on replay irreversible is not emitted by fork database, so emit it explicitly here
  + if( s == controller::block_status::irreversible )
  + emit( self.irreversible_block, new_header_state );
  if ( read_mode != db_read_mode::IRREVERSIBLE ) {
  maybe_switch_forks( s );
  