add AnalyticDBMySQL for vectorstore.

[freamdx]

AnalyticDB MySQL vector store.

about AnalyticDB MySQL, please visit
    [AnalyticDB MySQL official site](https://www.alibabacloud.com/en/product/analyticdb-for-mysql)

For example:
.. code-block:: python
    def create_adb_vectorstore(
        documents: list[Document],
        model_name: str = "text-embedding-v4"
    ) -> VectorStore:
        from langchain_community.embeddings import DashScopeEmbeddings
        from langchain_community.vectorstores import AnalyticDBMySQL

        embeddings = DashScopeEmbeddings(
            model=model_name,
            dashscope_api_key=os.getenv("DASHSCOPE_API_KEY"),
        )

        vectorstore = AnalyticDBMySQL(embedding=embeddings)
        return vectorstore.from_documents(
            documents=documents,
            embedding=embeddings,
        )