Closes #2634: Add TaskanaEngine.clearSessionCache to clear cache of underlying SQL session

lib/taskana-core/src/main/java/pro/taskana/common/api/TaskanaEngine.java

@@ -246,6 +246,9 @@ public interface TaskanaEngine {
    */
   CurrentUserContext getCurrentUserContext();
 
+  /** Clears the cache of the underlying local SQL session. */
+  void clearSqlSessionCache();
+
   /**
    * Connection management mode. Controls the connection handling of taskana
    *

lib/taskana-core/src/main/java/pro/taskana/common/internal/TaskanaEngineImpl.java

@@ -385,6 +385,11 @@ public class TaskanaEngineImpl implements TaskanaEngine {
     return currentUserContext;
   }
 
+  @Override
+  public void clearSqlSessionCache() {
+    sessionManager.clearCache();
+  }
+
   /**
    * This method creates the sqlSessionManager of myBatis. It integrates all the SQL mappers and
    * sets the databaseId attribute.