[Feature][Core] Add PendingJobs info in the response of GetOverviewOperation

docs/en/seatunnel-engine/rest-api-v2.md

@@ -60,6 +60,7 @@ Please refer [security](security.md)
     "unassignedSlot":"0",
     "works":"1",
     "runningJobs":"0",
+    "pendingJobs":"0",
     "finishedJobs":"0",
     "failedJobs":"0",
     "cancelledJobs":"0"

docs/zh/seatunnel-engine/rest-api-v2.md

@@ -58,6 +58,7 @@ seatunnel:
     "unassignedSlot":"0",
     "works":"1",
     "runningJobs":"0",
+    "pendingJobs":"0",
     "finishedJobs":"0",
     "failedJobs":"0",
     "cancelledJobs":"0"

seatunnel-e2e/seatunnel-engine-e2e/connector-seatunnel-e2e-base/src/test/java/org/apache/seatunnel/engine/e2e/RestApiIT.java

@@ -667,7 +667,8 @@ public void testOverview() {
                                                 .statusCode(200)
                                                 .body("projectVersion", notNullValue())
                                                 .body("totalSlot", equalTo("40"))
-                                                .body("workers", equalTo("2"));
+                                                .body("workers", equalTo("2"))
+                                                .body("pendingJobs", notNullValue());
                                         given().get(
                                                         HOST
                                                                 + value
@@ -680,7 +681,8 @@ public void testOverview() {
                                                 .statusCode(200)
                                                 .body("projectVersion", notNullValue())
                                                 .body("totalSlot", equalTo("40"))
-                                                .body("workers", equalTo("2"));
+                                                .body("workers", equalTo("2"))
+                                                .body("pendingJobs", notNullValue());
                                     });
                         });
     }

seatunnel-engine/seatunnel-engine-server/src/main/java/org/apache/seatunnel/engine/server/CoordinatorService.java

@@ -1079,6 +1079,10 @@ protected IMap<Long, HashMap<TaskLocation, SeaTunnelMetricsContext>> getMetricsI
         return metricsImap;
     }
 
+    public int getPendingJobCount() {
+        return pendingJobQueue.getJobIdMap().size();
+    }
+
     @VisibleForTesting
     public PeekBlockingQueue<PendingJobInfo> getPendingJobQueue() {
         return pendingJobQueue;

seatunnel-engine/seatunnel-engine-server/src/main/java/org/apache/seatunnel/engine/server/resourcemanager/opeartion/GetOverviewOperation.java

@@ -89,6 +89,7 @@ public static OverviewInfo getOverviewInfo(
         overviewInfo.setTotalSlot(assignedSlots.size() + unassignedSlots.size());
         overviewInfo.setUnassignedSlot(unassignedSlots.size());
         overviewInfo.setWorkers(resourceManager.workerCount(tags));
+        overviewInfo.setPendingJobs(server.getCoordinatorService().getPendingJobCount());
         overviewInfo.setRunningJobs(
                 nodeEngine.getHazelcastInstance().getMap(Constant.IMAP_RUNNING_JOB_INFO).size());
         overviewInfo.setFailedJobs(

seatunnel-engine/seatunnel-engine-server/src/main/java/org/apache/seatunnel/engine/server/resourcemanager/resource/OverviewInfo.java

@@ -27,6 +27,7 @@ public class OverviewInfo implements Serializable {
     private String gitCommitAbbrev;
     private int totalSlot;
     private int unassignedSlot;
+    private long pendingJobs;
     private long runningJobs;
     private long finishedJobs;
     private long failedJobs;