message: Update NextRequest based on new expires type
diff: @@ -464,7 +464,7 @@ pub struct SequencePair {
  /// for getting next messages for pull based consumers.
  #[derive(Debug, Default, Serialize, Deserialize, Clone, Copy)]
  pub(crate) struct NextRequest {
  - pub expires: DateTime,
  + pub expires: Option<usize>,
  pub batch: Option<usize>,
  pub no_wait: Option<bool>,
  }
  