Super-Refactor Refactor all source code for better development experiment:

Old source code:

1. others folder contains non - related system stuffs
2. backend_server: old server

Refactor source code

1. api folder: contain all APIS for every UC
2. db: database Management, Manipulation, and Monitoring
3. static & template: front end code folder for Flask server
4. refactor_server: main server! Pls run this file, plssss!!!!!

That's all!