wip, support highlight and select state

src/mol-geo/representation/index.ts

src/mol-geo/representation/structure/bond.ts

src/mol-geo/representation/structure/index.ts

src/mol-geo/representation/structure/point.ts

src/mol-geo/representation/structure/spacefill.ts

src/mol-geo/representation/structure/utils.ts

src/mol-geo/representation/volume/index.ts

src/mol-geo/representation/volume/surface.ts

src/mol-geo/util/flag-data.ts

src/mol-gl/_spec/renderer.spec.ts

src/mol-gl/shader/mesh.frag

src/mol-model/loci.ts

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

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

src/mol-view/label.ts

src/mol-view/state/transform.ts

src/mol-view/viewer.ts