message: allow empty clades, don't show clade definition in sequence tooltip
diff: @@ -73,16 +73,12 @@ export function LabelTooltip({ sequence, showTooltip }: LabelTooltipProps) {
  <div>{`Alignment score ${alignmentScore}`}</div>
  <div>{`Alignment start ${alnStartOneBased}`}</div>
  <div>{`Alignment end ${alnEndOneBased}`}</div>
  - <div>{`Clades ${cladesList}`}</div>
  + <div>{`Clades ${cladesList || '--'}`}</div>
  <div>{`Total mutations: ${totalMutations}`}</div>
  <div>
  <div>{`Mutations:`}</div>
  <ul>{mutationItems}</ul>
  </div>
  - <div>
  - <div>{`Mutations per clade:`}</div>
  - <ul>{cladeMutationItems}</ul>
  - </div>
  <div>{`Total gaps: ${totalGaps}`}</div>
  <div>{`Total Ns: ${totalNs}`}</div>
  <div>
  