extracted TokenManager into modules

src/transaction-hub-in/trace-retrieval-microservice/app/messaging/MessageHandler.py

-from authentication.token_manager import TokenManager
+from security.token_manager import TokenManager
 import network_constants
 from database.entities.transaction import Transaction
 from database.repository import Repository
@@ -114,13 +114,9 @@ class MessageHandler:
 
         return flattened
 
-    def handle_blockchain_transaction(self, transaction: Dict):
+    def _fetch_schema_information(self, use_case: str) -> Dict:
         jwt_token = TokenManager.getInstance().getToken()
         
-        transaction_data = transaction
-
-        use_case = transaction_data["ApplicationType"]
-
         # query schema information
         url = f'https://{network_constants.BUSINESS_LOGIC_HOSTNAME}:{network_constants.BUSINESS_LOGIC_REST_PORT}/api/use-cases/{use_case}/schema'
 
@@ -136,11 +132,22 @@ class MessageHandler:
         print(f"RESPONSE: {response.text}")
 
         if response.status_code != 200:
+            raise ValueError("no schema information available")
+        
+        return json.loads(response.text)
+
+    def handle_blockchain_transaction(self, transaction: Dict):
+        transaction_data = transaction
+
+        use_case = transaction_data["ApplicationType"]
+
+        try:
+            data = self._fetch_schema_information(use_case)
+        except ValueError as e:
+            print(f"{e}")
             MessageHandler._repository.add_failed_transaction(transaction)
             return
 
-        data = json.loads(response.text)
-
         mappings = data["mappings"]
         flattened = self._flatten_transaction(transaction_data, mappings)