Refactor @dgmjs/core
- [x] Move `createPointerEvent`, `createTouchEvent` to `editor` (no export)
- [x] Don't export `constants`
- [x] Rename `renderOnCanvas` to `drawShapesOnCanvas` (and remove `canvasUtils`?)
- [x] Rename functions in `macro` (e.g. `moveMultipleShapes` to `moveShapes`)
- [x] Separate `exportUtils` to `@dgmjs/export` package?
