function getWorstNumericDeltaForIndex(diffs, compareItemIndex, baseItemIndex) {
  const matchingDiffs = getMatchingDiffsForIndex(diffs, compareItemIndex, baseItemIndex);
  const numericDiffs = matchingDiffs.filter(isNumericAuditDiff);
  if (!numericDiffs.length) return undefined;
  return Math.max(...numericDiffs.map(diff => getDeltaStats(diff).delta));
}
Given the array of all diffs for an audit, determine the worst numeric delta for a particular row.
Used for sorting.

@param {Array<LHCI.AuditDiff>} diffs
@param {number|undefined} compareItemIndex
@param {number|undefined} baseItemIndex
@return {number|undefined}