Fed-BioMed v3.4 new release

Fed-BioMed v3.4 is now available. Here are some key new features:

• node-side differential privacy using Opacus notebook
• node GUI for managing shared data
• single Nvidia GPU training acceleration for PyTorch
• new tutorials and notebooks
• refactoring and testing for robustness and code maturity

All the new specifics are in the Fed-BioMed CHANGELOG.