Add support for Kotlin's `Result`

### Is your feature request related to a problem? Please describe.

```kt
@GET("me")
suspend fun getUser(): Result<User>
```

Refs https://github.com/square/retrofit/issues/3558.

### Describe the solution you'd like

Refs https://github.com/square/retrofit/pull/4018.

### Describe alternatives you've considered

_No response_

### Additional context

_No response_