Refactoring Structure data model

src/mol-data/int/impl/sorted-array.ts

src/mol-data/int/sorted-array.ts

src/mol-data/util/sort.ts

src/mol-math/geometry/symmetry-operator.ts

src/mol-model/structure/export/mmcif.ts

src/mol-model/structure/query/generators.ts

src/mol-model/structure/query/properties.ts

src/mol-model/structure/query/selection.ts

src/mol-model/structure/structure.ts

src/mol-model/structure/structure/element/group.ts

src/mol-model/structure/structure/element/impl/set.ts

src/mol-model/structure/structure/element/set.ts

src/mol-model/structure/structure/structure.ts

src/mol-model/structure/structure/symmetry.ts

src/mol-model/structure/structure/unit.ts

src/mol-model/structure/structure/unit/bonds/compute.ts

src/mol-model/structure/structure/unit/bonds/data.ts

src/mol-model/structure/structure/util/boundary.ts

src/mol-model/structure/structure/util/lookup3d.ts

src/perf-tests/structure.ts