Simplified some modules

src/mol-base/collections/_spec/iterators.spec.ts

src/mol-base/collections/integer.ts

src/mol-base/collections/iterator.ts

src/mol-data/_spec/atom-set.spec.ts

src/mol-data/model/builders/mmcif.ts

src/mol-data/model/properties/computed.ts

src/mol-data/model/properties/hierarchy.ts

src/mol-data/model/utils/hierarchy-keys.ts

src/mol-data/query.ts

src/mol-data/query/generators.ts

src/mol-data/query/query.ts

src/mol-data/query/selection.ts

src/mol-data/structure.ts

src/mol-data/structure/atom.ts

src/mol-data/structure/atom/set.ts

src/mol-data/structure/atom/set/builder.ts

src/mol-data/structure/atom/set/impl.ts

src/mol-data/structure/atom/set/properties.ts

src/mol-data/structure/base.ts

src/mol-data/structure/structure.ts