Mdev-10664 Add statuses about optimistic parallel replication stalls

In this commit we are adding three more status variable to SHOW SLAVE
STATUS.  Slave_DDL_Events and Slave_Non_Transactional_Events.

Slave_DDL_Groups:- This status variable counts the occurrence of DDL
statements

Slave_Non_Transactional_Groups:- This variable count the occurrence
of non-transnational event group.

Slave_Transactional_Groups:- This variable count the occurrence
of transnational event group.

Patch Credit:- Kristian Nielsen

mysql-test/suite/multi_source/multi_parallel_loop.inc

@@ -0,0 +1,19 @@
+#create a table,insert data and drop table
+
+#parameters
+#  loop_counter
+#  table_engine
+--echo ##Running CURD operation
+--disable_query_log
+while ($loop_counter)
+{
+  #DDL statement
+  --eval create table t1(a int primary key) engine=$table_engine;
+
+  #non trans update statement
+  insert into t1 values(1);
+  insert into t1 values(2);
+  drop table t1;
+  --dec $loop_counter
+}
+--enable_query_log