Refactor form update handling in API endpoints and models

- Introduced a new function to parse JSON values in endpoints.py for improved data handling.
- Updated extract_form_update_from_flow_nodes to return structured data instead of strings.
- Changed formUpdate field in ProcessResponse_chat model to use Any type with a default empty dictionary for better flexibility in handling updates.

src/schemas/models.py

@@ -1,5 +1,5 @@
 from pydantic import BaseModel, Field
-from typing import Optional
+from typing import Any, Optional
 
 class ProcessRequest_chat(BaseModel):
     sessionId: str = Field(..., max_length=64)
@@ -11,7 +11,7 @@ class ProcessResponse_chat(BaseModel):
     sessionId: str = Field(..., max_length=64)
     timeStamp: str = Field(..., max_length=32)
     outputText: str = Field(...)
-    formUpdate: str = Field(default="")
+    formUpdate: Any = Field(default_factory=dict)
     nextStage: str = Field(..., max_length=32)
     nextStageCode: str = Field(..., max_length=4)
     code: str = Field(..., max_length=4)