Add wait event for rewind worker

Author: pashkinelfe

src/backend/utils/activity/wait_event_names.txt

@@ -55,6 +55,7 @@ ARCHIVER_MAIN	"Waiting in main loop of archiver process."
 AUTOVACUUM_MAIN	"Waiting in main loop of autovacuum launcher process."
 BGWRITER_HIBERNATE	"Waiting in background writer process, hibernating."
 BGWRITER_MAIN	"Waiting in main loop of background writer process."
+REWIND_WORKER_MAIN	"Waiting in main loop of rewind worker process."
 CHECKPOINTER_MAIN	"Waiting in main loop of checkpointer process."
 LOGICAL_APPLY_MAIN	"Waiting in main loop of logical replication apply process."
 LOGICAL_LAUNCHER_MAIN	"Waiting in main loop of logical replication launcher process."