wip, direct volume

src/apps/structure-info/volume.ts

src/mol-geo/geometry/color-data.ts

src/mol-geo/geometry/direct-volume/direct-volume.ts

src/mol-geo/geometry/direct-volume/transfer-function.ts

src/mol-geo/geometry/marker-data.ts

src/mol-geo/geometry/size-data.ts

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

src/mol-geo/representation/volume/isosurface-mesh.ts

src/mol-gl/render-object.ts

src/mol-gl/renderable/direct-volume.ts

src/mol-gl/renderable/schema.ts

src/mol-gl/renderable/util.ts

src/mol-gl/shader/direct-volume.frag

src/mol-gl/webgl/compat.ts

src/mol-gl/webgl/context.ts

src/mol-gl/webgl/render-target.ts

src/mol-gl/webgl/texture.ts

src/mol-gl/webgl/uniform.ts

src/mol-model/volume/data.ts