cebra/umap improvement

[yeshaokai]

• Fixed the issue with using cebra. GPT thinks that without 'self' keyword, compute_cebra_embedding function is a stand alone function.

[MMathisLab]

@yeshaokai adding streamlit isn't necessary for the core amadeusgpt, so one should pip install amadeusGPT[streamlit] for the GUI; I can confirm it works as is right now.