…gine#530)

…hain (volcengine#528)

* During the conversion process from langchain to veadk, correct the read and write operation logic of long-term memory

- Modify save_session.py to:
1. Filter out messages with potentially empty content in AIMessage
2. Correctly handle ToolMessage, ignoring it regardless of its content
3. Only save HumanMessage and AIMessage messages that have actual content

- In viking_memory.py:
1. Modify the batch() method:
   - Add the corresponding result to the results list for each operation
   - PutOp: Add None
   - GetOp: Correctly add the result of self._apply_get_op(op)
   - SearchOp: Correctly add the result of self._apply_search_op(op)
2. Modify the _apply_search_op() method:
   - Use op.limit or 1 to correctly handle search limits

* release new version to 0.5.25

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Co-authored-by: yaozheng-fang <fangyaozheng@bytedance.com>