优化存储读写，增加一些查询接口

flowable-core/src/main/java/com/lanyuanxiaoyao/flowable/core/manager/FlowableManager.java

@@ -36,6 +36,10 @@ public abstract class FlowableManager {
     this.repository = repository;
   }
 
+  public boolean existsNode(String nodeId) {
+    return repository.existsNode(nodeId);
+  }
+
   public List<FlowableNode> listNodes() {
     return repository.listNodes();
   }
@@ -44,6 +48,10 @@ public abstract class FlowableManager {
     return repository.getNode(nodeId);
   }
 
+  public boolean existsInstance(String instanceId) {
+    return repository.existsInstance(instanceId);
+  }
+
   public List<FlowableInstance> listInstances() {
     return repository.listInstances();
   }
@@ -52,6 +60,10 @@ public abstract class FlowableManager {
     return repository.getInstance(instantId);
   }
 
+  public boolean existsHistory(String historyId) {
+    return repository.existsHistory(historyId);
+  }
+
   public List<FlowableHistory> listHistories(String instanceId) {
     return repository.listHistories(instanceId);
   }

flowable-core/src/main/java/com/lanyuanxiaoyao/flowable/core/repository/FlowableRepository.java

@@ -12,6 +12,8 @@ import java.util.List;
  * @version 20241231
  */
 public interface FlowableRepository {
+  boolean existsNode(String nodeId);
+
   void saveNode(FlowableNode node);
 
   void saveNode(List<FlowableNode> nodes);
@@ -20,12 +22,16 @@ public interface FlowableRepository {
 
   List<FlowableNode> listNodes();
 
+  boolean existsInstance(String instanceId);
+
   void saveInstance(FlowableInstance instance);
 
   FlowableInstance getInstance(String instantId);
 
   List<FlowableInstance> listInstances();
 
+  boolean existsHistory(String historyId);
+
   void saveHistory(FlowableHistory history);
 
   FlowableHistory getHistory(String historyId);