community[patch]: Extend Baichuan model with tool support (#24529)

**Description:** Expanded the chat model functionality to support tools
in the 'baichuan.py' file. Updated module imports and added tool object
handling in message conversions. Additional changes include the
implementation of tool binding and related unit tests. The alterations
offer enhanced model capabilities by enabling interaction with tool-like
objects.

---------

Co-authored-by: ccurme <chester.curme@gmail.com>

libs/community/tests/unit_tests/chat_models/test_baichuan.py

@@ -8,6 +8,7 @@ from langchain_core.messages import (
     HumanMessage,
     HumanMessageChunk,
     SystemMessage,
+    ToolMessage,
 )
 from langchain_core.pydantic_v1 import SecretStr
 from pytest import CaptureFixture, MonkeyPatch
@@ -58,6 +59,18 @@ def test__convert_message_to_dict_system() -> None:
     assert result == expected_output
 
 
+def test__convert_message_to_dict_tool() -> None:
+    message = ToolMessage(name="foo", content="bar", tool_call_id="abc123")
+    result = _convert_message_to_dict(message)
+    expected_output = {
+        "name": "foo",
+        "content": "bar",
+        "tool_call_id": "abc123",
+        "role": "tool",
+    }
+    assert result == expected_output
+
+
 def test__convert_message_to_dict_function() -> None:
     message = FunctionMessage(name="foo", content="bar")
     with pytest.raises(TypeError) as e: