Fix flakyness in citus_split_shard_by_split_points_deferred_drop

In CI we would sometimes get this failure:
```diff
 -- The original shard is marked for deferred drop with policy_type = 2.
 -- The previous shard should be dropped at the beginning of the second split call
 SELECT * from pg_dist_cleanup;
  record_id | operation_id | object_type |                               object_name                                | node_group_id | policy_type
 -----------+--------------+-------------+--------------------------------------------------------------------------+---------------+-------------
+        60 |          778 |           3 | citus_shard_split_slot_18_21216_778                                      |            16 |           0
        512 |          778 |           1 | citus_split_shard_by_split_points_deferred_schema.table_to_split_8981001 |            16 |           2
-(1 row)
+(2 rows)
```

Replication slots sometimes cannot be deleted right away. Which is hard
to resolve, but luckily we can filter these cleanup records out easily
by filtering by policy_type.

While debugging this issue I learnt that we did not use
GetNextCleanupRecordId in all places where we created cleanup
records. This caused test failures when running tests multiple times,
when they set citus.next_cleanup_record_id. So this PR fixes that too.

src/backend/distributed/operations/shard_cleaner.c

@@ -514,19 +514,16 @@ InsertCleanupRecordInSubtransaction(CleanupObject objectType,
 	 */
 	Assert(CurrentOperationId != INVALID_OPERATION_ID);
 
-	StringInfo sequenceName = makeStringInfo();
-	appendStringInfo(sequenceName, "%s.%s",
-					 PG_CATALOG,
-					 CLEANUPRECORDID_SEQUENCE_NAME);
+	uint64 recordId = GetNextCleanupRecordId();
 
 	StringInfo command = makeStringInfo();
 	appendStringInfo(command,
 					 "INSERT INTO %s.%s "
 					 " (record_id, operation_id, object_type, object_name, node_group_id, policy_type) "
-					 " VALUES ( nextval('%s'), " UINT64_FORMAT ", %d, %s, %d, %d)",
+					 " VALUES ( %lu, " UINT64_FORMAT ", %d, %s, %d, %d)",
 					 PG_CATALOG,
 					 PG_DIST_CLEANUP,
-					 sequenceName->data,
+					 recordId,
 					 CurrentOperationId,
 					 objectType,
 					 quote_literal_cstr(objectName),

src/test/regress/expected/citus_split_shard_by_split_points_deferred_drop.out

@@ -64,10 +64,10 @@ SELECT pg_catalog.citus_split_shard_by_split_points(
 
 -- The original shard is marked for deferred drop with policy_type = 2.
 -- The previous shard should be dropped at the beginning of the second split call
-SELECT * from pg_dist_cleanup;
+SELECT * FROM pg_dist_cleanup WHERE policy_type = 2;
  record_id | operation_id | object_type |                               object_name                                | node_group_id | policy_type
 ---------------------------------------------------------------------
-       512 |          778 |           1 | citus_split_shard_by_split_points_deferred_schema.table_to_split_8981001 |            16 |           2
+       526 |          778 |           1 | citus_split_shard_by_split_points_deferred_schema.table_to_split_8981001 |            16 |           2
 (1 row)
 
 -- One of the physical shards should not be deleted, the other one should.
@@ -90,8 +90,12 @@ SELECT relname FROM pg_class where relname LIKE '%table_to_split_%' AND relkind
 
 -- Perform deferred drop cleanup.
 \c - postgres - :master_port
-CALL citus_cleanup_orphaned_resources();
-NOTICE:  cleaned up 1 orphaned resources
+SELECT public.wait_for_resource_cleanup();
+ wait_for_resource_cleanup
+---------------------------------------------------------------------
+
+(1 row)
+
 -- Clenaup has been done.
 SELECT * from pg_dist_cleanup;
  record_id | operation_id | object_type | object_name | node_group_id | policy_type

src/test/regress/sql/citus_split_shard_by_split_points_deferred_drop.sql

@@ -51,7 +51,7 @@ SELECT pg_catalog.citus_split_shard_by_split_points(
 
 -- The original shard is marked for deferred drop with policy_type = 2.
 -- The previous shard should be dropped at the beginning of the second split call
-SELECT * from pg_dist_cleanup;
+SELECT * FROM pg_dist_cleanup WHERE policy_type = 2;
 
 -- One of the physical shards should not be deleted, the other one should.
 \c - - - :worker_1_port
@@ -62,7 +62,7 @@ SELECT relname FROM pg_class where relname LIKE '%table_to_split_%' AND relkind
 
 -- Perform deferred drop cleanup.
 \c - postgres - :master_port
-CALL citus_cleanup_orphaned_resources();
+SELECT public.wait_for_resource_cleanup();
 
 -- Clenaup has been done.
 SELECT * from pg_dist_cleanup;