Validation and Error Handling Framework

[Mkalbani]

Create comprehensive input validation and error handling system throughout the application.

Tasks:
Set up class-validator with custom validation decorators
Implement global exception filters for consistent error responses
Create custom exception classes for different error types
Set up validation pipes with detailed error messages
Implement request sanitization and security validation
Create error response formatting standards
Set up validation for complex nested objects and arrays
Implement file upload validation and security checks
Create user-friendly error messages and codes
Set up error tracking and reporting mechanisms

Acceptance Criteria:
All inputs are validated with clear error messages
Exceptions are handled consistently across the application
Security vulnerabilities from invalid input are prevented
Error responses follow standardized format
Validation errors are logged and trackable