fix error response disformat usage (#2213)

### What problem does this PR solve?

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

api/apps/canvas_app.py

@@ -19,7 +19,7 @@ from flask import request, Response
 from flask_login import login_required, current_user
 from api.db.services.canvas_service import CanvasTemplateService, UserCanvasService
 from api.utils import get_uuid
-from api.utils.api_utils import get_json_result, server_error_response, validate_request
+from api.utils.api_utils import get_json_result, server_error_response, validate_request, get_data_error_result
 from agent.canvas import Canvas
 from peewee import MySQLDatabase, PostgresqlDatabase
 
@@ -61,7 +61,7 @@ def save():
             return server_error_response(ValueError("Duplicated title."))
         req["id"] = get_uuid()
         if not UserCanvasService.save(**req):
-            return server_error_response("Fail to save canvas.")
+            return get_data_error_result(retmsg="Fail to save canvas.")
     else:
         UserCanvasService.update_by_id(req["id"], req)
 
@@ -73,7 +73,7 @@ def save():
 def get(canvas_id):
     e, c = UserCanvasService.get_by_id(canvas_id)
     if not e:
-        return server_error_response("canvas not found.")
+        return get_data_error_result(retmsg="canvas not found.")
     return get_json_result(data=c.to_dict())
 
 
@@ -85,7 +85,7 @@ def run():
     stream = req.get("stream", True)
     e, cvs = UserCanvasService.get_by_id(req["id"])
     if not e:
-        return server_error_response("canvas not found.")
+        return get_data_error_result(retmsg="canvas not found.")
 
     if not isinstance(cvs.dsl, str):
         cvs.dsl = json.dumps(cvs.dsl, ensure_ascii=False)
@@ -151,7 +151,7 @@ def reset():
     try:
         e, user_canvas = UserCanvasService.get_by_id(req["id"])
         if not e:
-            return server_error_response("canvas not found.")
+            return get_data_error_result(retmsg="canvas not found.")
 
         canvas = Canvas(json.dumps(user_canvas.dsl), current_user.id)
         canvas.reset()