refactor api util (#2849)

### What problem does this PR solve?


### Type of change

- [x] Refactoring

api/apps/api_app.py

 from flask_login import login_required, current_user
 
 from api.db import FileType, LLMType, ParserType, FileSource
-from api.db.db_models import APIToken, API4Conversation, Task, File
+from api.db.db_models import APIToken, Task, File
 from api.db.services import duplicate_name
 from api.db.services.api_service import APITokenService, API4ConversationService
 from api.db.services.dialog_service import DialogService, chat
 from api.db.services.user_service import UserTenantService
 from api.settings import RetCode, retrievaler
 from api.utils import get_uuid, current_timestamp, datetime_format
-from api.utils.api_utils import server_error_response, get_data_error_result, get_json_result, validate_request
-from itsdangerous import URLSafeTimedSerializer
+from api.utils.api_utils import server_error_response, get_data_error_result, get_json_result, validate_request, \
+    generate_confirmation_token
 
 from api.utils.file_utils import filename_type, thumbnail
 from rag.nlp import keyword_extraction
 from rag.utils.storage_factory import STORAGE_IMPL
 
-from api.db.services.canvas_service import CanvasTemplateService, UserCanvasService
+from api.db.services.canvas_service import UserCanvasService
 from agent.canvas import Canvas
 from functools import partial
 
 
-def generate_confirmation_token(tenent_id):
-    serializer = URLSafeTimedSerializer(tenent_id)
-    return "ragflow-" + serializer.dumps(get_uuid(), salt=tenent_id)[2:34]
-
-
 @manager.route('/new_token', methods=['POST'])
 @login_required
 def new_token():

api/apps/system_app.py

 from datetime import datetime
 
 from flask_login import login_required, current_user
-
-from api.apps.api_app import generate_confirmation_token
 from api.db.services.api_service import APITokenService
 from api.db.services.knowledgebase_service import KnowledgebaseService
 from api.db.services.user_service import UserTenantService
 from api.settings import DATABASE_TYPE
 from api.utils import current_timestamp, datetime_format
-from api.utils.api_utils import get_json_result, request, get_data_error_result, server_error_response
+from api.utils.api_utils import get_json_result, get_data_error_result, server_error_response, \
+    generate_confirmation_token
 from api.versions import get_rag_version
-from rag.settings import SVR_QUEUE_NAME
 from rag.utils.es_conn import ELASTICSEARCH
 from rag.utils.storage_factory import STORAGE_IMPL, STORAGE_IMPL_TYPE
 from timeit import default_timer as timer

api/utils/api_utils.py

     Response, jsonify, send_file, make_response,
     request as flask_request,
 )
+from itsdangerous import URLSafeTimedSerializer
 from werkzeug.http import HTTP_STATUS_CODES
 
 from api.db.db_models import APIToken
     stat_logger, CLIENT_AUTHENTICATION, HTTP_APP_KEY, SECRET_KEY
 )
 from api.settings import RetCode
-from api.utils import CustomJSONEncoder
+from api.utils import CustomJSONEncoder, get_uuid
 from api.utils import json_dumps
 
 requests.models.complexjson.dumps = functools.partial(
         k.replace(
             '_',
             '-').upper(): v for k,
-        v in kwargs.get(
+                                v in kwargs.get(
             'headers',
             {}).items()}
     prepped = requests.Request(**kwargs).prepare()
 
     return decorated_function
 
+
 def get_result(retcode=RetCode.SUCCESS, retmsg='error', data=None):
     if retcode == 0:
         if data is not None:
         else:
             response = {"code": retcode}
     else:
-            response = {"code": retcode, "message": retmsg}
+        response = {"code": retcode, "message": retmsg}
     return jsonify(response)
 
-def get_error_data_result(retmsg='Sorry! Data missing!',retcode=RetCode.DATA_ERROR,
+
+def get_error_data_result(retmsg='Sorry! Data missing!', retcode=RetCode.DATA_ERROR,
                           ):
     import re
     result_dict = {
             continue
         else:
             response[key] = value
-    return jsonify(response)
+    return jsonify(response)
+
+
+def generate_confirmation_token(tenent_id):
+    serializer = URLSafeTimedSerializer(tenent_id)
+    return "ragflow-" + serializer.dumps(get_uuid(), salt=tenent_id)[2:34]