removed canvas app

package.json

src/apps/canvas/app.ts

src/apps/canvas/assembly-symmetry.ts

src/apps/canvas/component/app.tsx

src/apps/canvas/component/representation.tsx

src/apps/canvas/component/structure-view.tsx

src/apps/canvas/component/viewport.tsx

src/apps/canvas/component/volume-view.tsx

src/apps/canvas/examples.ts

src/apps/canvas/index.html

src/apps/canvas/index.ts

src/apps/canvas/structure-view.ts

src/apps/canvas/util.ts

src/apps/canvas/volume-view.ts