Feat: conversation variable & variable assigner node (#7222)

Signed-off-by: -LAN- <laipz8200@outlook.com>
Co-authored-by: Joel <iamjoel007@gmail.com>
Co-authored-by: -LAN- <laipz8200@outlook.com>

api/models/tool.py

@@ -2,7 +2,8 @@ import json
 from enum import Enum
 
 from extensions.ext_database import db
-from models import StringUUID
+
+from .types import StringUUID
 
 
 class ToolProviderName(Enum):