message: fix: guard from empty and incorrect ranges
diff: @@ -95,7 +95,9 @@ int CoordinateMapper::refToAln(int refPos) const {
  }
  Range CoordinateMapper::alnToRef(const Range& alnRange) const {
  - precondition_less(alnRange.begin, alnRange.end);
  + if (alnRange.begin >= alnRange.end) {
  + return Range{alnRange.begin, alnRange.begin};
  + }
  const Range refRange{
  .begin = alnToRef(alnRange.begin),
  .end = alnToRef(alnRange.end - 1) + 1,
  @@ -105,7 +107,9 @@ Range CoordinateMapper::alnToRef(const Range& alnRange) const {
  }
  Range CoordinateMapper::refToAln(const Range& refRange) const {
  - precondition_less(refRange.begin, refRange.end);
  + if (refRange.begin >= refRange.end) {
  + return Range{refRange.begin, refRange.begin};
  + }
  const Range alnRange{
  .begin = refToAln(refRange.begin),
  .end = refToAln(refRange.end - 1) + 1,
  