wip fog and shader cleanup

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/volume/surface.ts

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

src/mol-gl/renderable/schema.ts

src/mol-gl/renderer.ts

src/mol-gl/shader/chunks/apply-fog.glsl

src/mol-gl/shader/chunks/assign-position.glsl

src/mol-gl/shader/chunks/common-frag-params.glsl

src/mol-gl/shader/mesh.frag

src/mol-gl/shader/mesh.vert

src/mol-gl/shader/point.frag

src/mol-gl/shader/point.vert

src/mol-view/camera/base.ts

src/mol-view/camera/orthographic.ts

src/mol-view/camera/perspective.ts