Refactor backend and frontend

[tiangolo]

Refactor backend and frontend.

• Simplify and update backend Dockerfiles.
• Refactor and simplify backend code, improve naming, imports, modules and "namespaces".
• Improve and simplify Vuex integration with TypeScript accessors.
• Standardize frontend components layout, buttons order, etc.
• Add local development scripts (to develop this project generator itself).
• Add logs to startup modules to detect errors early.
• Improve FastAPI dependency utilities, to simplify and reduce code (to require a superuser).
• Fix/update logic to update users.