Refactoring

[samuelrince]

Changelog:

• Use fastapi and uvicorn instead of Flask because of the better integration with pydantic data modeling and automatic swagger / openapi.json generation
• Add __init__.py for each packages
• Update docker images to run using uvicorn
• Update docs docker image to run on the same python version as the code + some fixes
• Restructure repository with api package and docs directory
• Update README.md with more instructions on how to launch the project