add ellipsoid repr showing mmcif thermal displacement

src/mol-geo/geometry/mesh/builder/ellipsoid.ts

src/mol-geo/geometry/mesh/builder/sphere.ts

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

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

src/mol-repr/structure/registry.ts

src/mol-repr/structure/representation/ellipsoid.ts

src/mol-repr/structure/visual/ellipsoid-mesh.ts