multimodel IHM is now parsed into separate models

src/apps/structure-info/model.ts

src/mol-data/db/column.ts

src/mol-data/db/table.ts

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

src/mol-model/structure/model/formats/mmcif/ihm.ts

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

src/mol-model/structure/model/properties/coarse/hierarchy.ts

...mol-model/structure/model/properties/utils/coarse-keys.ts

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