fix: use unit type for unimplemented api errors (see #12)

client/src/error.rs

@@ -34,7 +34,14 @@ macro_rules! api_errors {
  $field: $field_type
  ),*)?
  }
- ),*
+ ),*,
+ // "workaround" for #12
+ #[serde(other)]
+ #[error("not yet implemented ApiError")]
+ /// A fallback error to indicate that the error is not implemented (yet)
+ /// Because of a limitation from serde (see #12) you cannot access
+ /// `description` and `hint`
+ Other
  }
  };
 }