message: improve Model.hasSecondaryStructure
  check ModelSecondaryStructure.Provider.isApplicable
diff: @@ -30,6 +30,7 @@ import { Trajectory, ArrayTrajectory } from '../trajectory';
  import { Unit } from '../structure';
  import { SortedArray } from '../../../mol-data/int/sorted-array';
  import { PolymerType } from './types';
  +import { ModelSecondaryStructure } from '../../../mol-model-formats/structure/property/secondary-structure';
  /**
  * Interface to the "source data" of the molecule.
  @@ -318,12 +319,15 @@ export namespace Model {
  }
  export function hasSecondaryStructure(model: Model): boolean {
  - if (!MmcifFormat.is(model.sourceData)) return false;
  + if (MmcifFormat.is(model.sourceData)) {
  const { db } = model.sourceData.data;
  return (
  db.struct_conf.id.isDefined ||
  db.struct_sheet_range.id.isDefined
  );
  + } else {
  + return ModelSecondaryStructure.Provider.isApplicable(model);
  + }
  }
  const tmpAngles90 = Vec3.create(1.5707963, 1.5707963, 1.5707963); // in radians
  