refactored repr.mark

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

src/mol-repr/shape/representation.ts

src/mol-repr/structure/complex-visual.ts

src/mol-repr/structure/units-visual.ts

src/mol-repr/structure/visual/carbohydrate-link-cylinder.ts

src/mol-repr/structure/visual/carbohydrate-symbol-mesh.ts

...r/structure/visual/carbohydrate-terminal-link-cylinder.ts

...ol-repr/structure/visual/cross-link-restraint-cylinder.ts

src/mol-repr/structure/visual/element-point.ts

src/mol-repr/structure/visual/element-sphere.ts

src/mol-repr/structure/visual/gaussian-density-point.ts

src/mol-repr/structure/visual/gaussian-density-volume.ts

src/mol-repr/structure/visual/gaussian-surface-mesh.ts

src/mol-repr/structure/visual/gaussian-surface-wireframe.ts

src/mol-repr/structure/visual/inter-unit-link-cylinder.ts

src/mol-repr/structure/visual/intra-unit-link-cylinder.ts

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

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

src/mol-repr/structure/visual/polymer-direction-wedge.ts

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