community[minor]: integrate with model Yuan2.0 (#15411)

1. integrate with
[`Yuan2.0`](https://github.com/IEIT-Yuan/Yuan-2.0/blob/main/README-EN.md)
2. update `langchain.llms`
3. add a new doc for [Yuan2.0
integration](docs/docs/integrations/llms/yuan2.ipynb)

---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>
Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/community/tests/integration_tests/llms/test_yuan2.py

@@ -0,0 +1,33 @@
+"""Test Yuan2.0 API wrapper."""
+from langchain_core.outputs import LLMResult
+
+from langchain_community.llms import Yuan2
+
+
+def test_yuan2_call_method() -> None:
+    """Test valid call to Yuan2.0."""
+    llm = Yuan2(
+        infer_api="http://127.0.0.1:8000/yuan",
+        max_tokens=1024,
+        temp=1.0,
+        top_p=0.9,
+        top_k=40,
+        use_history=False,
+    )
+    output = llm("写一段快速排序算法。")
+    assert isinstance(output, str)
+
+
+def test_yuan2_generate_method() -> None:
+    """Test valid call to Yuan2.0 inference api."""
+    llm = Yuan2(
+        infer_api="http://127.0.0.1:8000/yuan",
+        max_tokens=1024,
+        temp=1.0,
+        top_p=0.9,
+        top_k=40,
+        use_history=False,
+    )
+    output = llm.generate(["who are you?"])
+    assert isinstance(output, LLMResult)
+    assert isinstance(output.generations, list)