Exit with message

_As a CLI developer, I want to be able to exit from app with message and code._

## API
```py
from candies.cli import cli, Arg, Exit

@cli
def divide(x: Arg[int], y: Arg[int]):
    if y == 0:
        raise Exit(f'Cannot divide {x} by zero')

    print(x / y)
```

## Requirements
- Code should be tested.