feat: todo crud operations

[DriLLFreAK100]

Included the following changes:

• Setup a basic structure for the service
  • generated - for auto-generated codes, e.g. diesel schema
  • modules - each module should be in its own folder with its routes, models, command, etc that are closely related
  • utils - for based funcs and utils used throughout the app
• Setup a basic Postgres structure for todo module
• Integrated dieselORM
• Implemented todo module with basic CRUD operations
• Included utils that encapsulate verbose codes dealing with general db, http ops