PG-188: Added a new column to monitor the query state.

Added missing test case files.

regression/expected/state.out

@@ -0,0 +1,31 @@
+CREATE EXTENSION pg_stat_monitor;
+SELECT pg_stat_monitor_reset();
+ pg_stat_monitor_reset 
+-----------------------
+ 
+(1 row)
+
+SELECT 1;
+ ?column? 
+----------
+        1
+(1 row)
+
+SELECT 1/0;   -- divide by zero
+ERROR:  division by zero
+SELECT query, state_code, state FROM pg_stat_monitor ORDER BY query COLLATE "C";
+                                      query                                       | state_code |        state        
+----------------------------------------------------------------------------------+------------+---------------------
+ SELECT $1 AS num                                                                 |          3 | FINISHED
+ SELECT 1/0;                                                                      |          4 | FINISHED WITH ERROR
+ SELECT pg_stat_monitor_reset();                                                  |          3 | FINISHED
+ SELECT query, state_code, state FROM pg_stat_monitor ORDER BY query COLLATE "C"; |          2 | ACTIVE
+(4 rows)
+
+SELECT pg_stat_monitor_reset();
+ pg_stat_monitor_reset 
+-----------------------
+ 
+(1 row)
+
+DROP EXTENSION pg_stat_monitor;

regression/sql/state.sql

@@ -0,0 +1,8 @@
+CREATE EXTENSION pg_stat_monitor;
+SELECT pg_stat_monitor_reset();
+SELECT 1;
+SELECT 1/0;   -- divide by zero
+
+SELECT query, state_code, state FROM pg_stat_monitor ORDER BY query COLLATE "C";
+SELECT pg_stat_monitor_reset();
+DROP EXTENSION pg_stat_monitor;