message: fix: op parsing
diff: @@ -77,12 +77,24 @@ impl OperationSimple {
  let c = self.contents.first()?.clone();
  match op_kind(&c)? {
  - "preendorsement" => serde_json::from_value(c)
  + "preendorsement" => {
  + let mut c = c;
  + let c_obj = c.as_object_mut()?;
  + c_obj.remove("kind");
  + c_obj.remove("metadata");
  + serde_json::from_value(c)
  .ok()
  - .map(OperationKind::Preendorsement),
  - "endorsement" => serde_json::from_value(c)
  + .map(OperationKind::Preendorsement)
  + },
  + "endorsement" => {
  + let mut c = c;
  + let c_obj = c.as_object_mut()?;
  + c_obj.remove("kind");
  + c_obj.remove("metadata");
  + serde_json::from_value(c)
  .ok()
  - .map(OperationKind::Endorsement),
  + .map(OperationKind::Endorsement)
  + },
  "failing_noop" => None,
  "proposals" | "ballot" => Some(OperationKind::Votes),
  "seed_nonce_revelation"
  