[feat 🎡] Request body validation

[devlopersabbir]

Create a request body validator with the below TODO

• Create a userModel.py file for the user request body
• Create a User class then will extend BaseModel which will come from pydantic
• Must use __init__.py file for package managing (required)
• Mention User model in http request body prams and also in http response
• Path & request body extra validations