Add setup.py for packaging

[simon824]

We can test python packages through step1+step2.

step 1: manually install dependencies (this step is not required after release)

Since dependencies with specified version numbers in the test-pypi repository may be missing, we need to manually install the dependencies first.

pip3 install -r requirement.txt

• requirement.txt

  
  openai==0.28.1
  retry==0.9.2
  tiktoken==0.5.1
  nltk==3.8.1
  gradio==4.19.2

decorator==5.1.1 requests==2.31.0 setuptools==67.6.1 urllib3==2.0.7

### step 2:  install `hugegraph-python`,`hugegraph-llm`
After that, we can install `hugegraph-python`,`hugegraph-llm` through the following command.

```bash 
pip install -i https://test.pypi.org/simple/ hugegraph-python==1.3.0.2
pip install -i https://test.pypi.org/simple/ hugegraph-llm==1.3.0.2