static findingToTableItem(hstsDirective, findingDescription, severity) {
    return {
      directive: hstsDirective,
      description: findingDescription,
      severity,
    };
  }
@param {string} hstsDirective
@param {LH.IcuMessage | string} findingDescription
@param {LH.IcuMessage=} severity
@return {LH.Audit.Details.TableItem}