replace the secret field from obfuscated to full-masked value (#24800)

Co-authored-by: charles liu <dearcharles.liu@gmail.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

api/core/helper/encrypter.py

     return token[:6] + "*" * 12 + token[-2:]
 
 
+def full_mask_token(token_length=20):
+    return "*" * token_length
+
+
 def encrypt_token(tenant_id: str, token: str):
     from models.account import Tenant
     from models.engine import db

api/fields/workflow_fields.py

             return {
                 "id": value.id,
                 "name": value.name,
-                "value": encrypter.obfuscated_token(value.value),
+                "value": encrypter.full_mask_token(),
                 "value_type": value.value_type.value,
                 "description": value.description,
             }