feat: add usename to pg_process_idle metric

Signed-off-by: rezaxd <r324r11@gmail.com>

Author: rezaxd

collector/pg_process_idle.go

@@ -52,11 +52,12 @@ func (PGProcessIdleCollector) Update(ctx context.Context, instance *instance, ch
 				SELECT
 				state,
 				application_name,
+    		usename,
 				SUM(EXTRACT(EPOCH FROM (CURRENT_TIMESTAMP - state_change))::bigint)::float AS process_idle_seconds_sum,
 				COUNT(*) AS process_idle_seconds_count
 				FROM pg_stat_activity
 				WHERE state ~ '^idle'
-				GROUP BY state, application_name
+				GROUP BY state, application_name, usename
 			),
 			buckets AS (
 				SELECT
@@ -78,12 +79,13 @@ func (PGProcessIdleCollector) Update(ctx context.Context, instance *instance, ch
 			SELECT
 			state,
 			application_name,
+   		usename,
 			process_idle_seconds_sum as seconds_sum,
 			process_idle_seconds_count as seconds_count,
 			ARRAY_AGG(le) AS seconds,
 			ARRAY_AGG(bucket) AS seconds_bucket
 			FROM metrics JOIN buckets USING (state, application_name)
-			GROUP BY 1, 2, 3, 4;`)
+			GROUP BY 1, 2, 3, 4, 5;`)
 
 	var state sql.NullString
 	var applicationName sql.NullString