message: fix: incorrect smp cluster ranges
  Looks like the code assumed that the positions of mutations in clusters were sorted ascending and took cluster range boundaries as first and last positions.
  But mutation positions were not sorted.
  This PR adds sorting.
diff: @@ -39,6 +39,10 @@ namespace Nextclade {
  previousPos = pos;
  }
  + for (auto& cluster : allClusters) {
  + std::sort(cluster.begin(), cluster.end());
  + }
  +
  return allClusters;
  }
  