CMD + D to Duplicate Selection (#982)

* cmd+d to duplicate selection

* use duplicateElement instead

* use duplicateElement instead

* Update actionDuplicateSelection.ts

* select the new duplicated element

* add locale

* use event.key instead of event.code

Co-authored-by: David Luzar <luzar.david@gmail.com>

src/actions/index.ts

@@ -6,6 +6,7 @@ export {
   actionSendToBack,
 } from "./actionZindex";
 export { actionSelectAll } from "./actionSelectAll";
+export { actionDuplicateSelection } from "./actionDuplicateSelection";
 export {
   actionChangeStrokeColor,
   actionChangeBackgroundColor,