add baidu vectordb as vector store (#11494)

docs/examples/vector_stores/BaiduVectorDBIndexDemo.ipynb

docs/module_guides/storing/vector_stores.md

...ctor_stores/llama-index-vector-stores-baiduvectordb/BUILD

...r_stores/llama-index-vector-stores-baiduvectordb/Makefile

..._stores/llama-index-vector-stores-baiduvectordb/README.md

...iduvectordb/llama_index/vector_stores/baiduvectordb/BUILD

...tordb/llama_index/vector_stores/baiduvectordb/__init__.py

...uvectordb/llama_index/vector_stores/baiduvectordb/base.py

...es/llama-index-vector-stores-baiduvectordb/pyproject.toml

...tores/llama-index-vector-stores-baiduvectordb/tests/BUILD

...llama-index-vector-stores-baiduvectordb/tests/__init__.py

...s-baiduvectordb/tests/test_vector_stores_baiduvectordb.py