improved low-poly geo (cylinder, sheet, tube, ribbon)

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

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

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

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

src/mol-geo/primitive/polygon.ts

src/mol-geo/primitive/primitive.ts

src/mol-geo/primitive/prism.ts

...odel-props/rcsb/representations/assembly-symmetry-axes.ts

src/mol-repr/structure/visual/nucleotide-block-mesh.ts

src/mol-repr/structure/visual/nucleotide-ring-mesh.ts

src/mol-repr/structure/visual/polymer-backbone-cylinder.ts

src/mol-repr/structure/visual/polymer-gap-cylinder.ts

src/mol-repr/structure/visual/polymer-trace-mesh.ts

src/mol-repr/structure/visual/polymer-tube-mesh.ts

src/mol-repr/structure/visual/util/link.ts