feat: AuthController for requests

[annikaholmqvist94]

For example: ```
@RestController
@RequestMapping("/api/auth")
public class AuthController {

private final AuthService authService;

public AuthController(AuthService authService) {
    this.authService = authService;
}

@PostMapping("/register")
public ResponseEntity<UserResponse> register(
        @Valid @RequestBody RegisterRequest request) {
    return ResponseEntity.ok(
        UserResponse.from(authService.register(request))
    );
}

@PostMapping("/login")
public ResponseEntity<AuthResponse> login(
        @Valid @RequestBody LoginRequest request) {
    String token = authService.login(request);
    return ResponseEntity.ok(new AuthResponse(token));
}

}