Improve API naming and scoping

### What needs to get done

Do not be repetitive on names

```
craft_application.services.package.PackageService
```

Can be refactored to

```
craft_application.services.package.Package
```

or

```
craft_application.services._package.Package
```

and accessed as

```
craft_application.services.Package
```

or

```
from craft_application import services
services.Package
```

### Why it needs to get done

- Easier use of the API
- Less repetition
- Better Scoping