[FIX] model: don't flatten command result

`array.flat()` is slow because it creates a new array (and allocates memory)

With this commit, we only execute `array.flat()` if the command as been refused
by one of the plugins (for possibly several resons)

`checkDispatchAllowed` self-time could take up to 4% of the total time when loading
a spreadsheet with lots of initial revisions.

Now it's 0.0% :)

closes #3190

X-original-commit: 4991b29
Signed-off-by: Rémi Rahir (rar) <[email protected]>
Signed-off-by: Lucas Lefèvre (lul) <[email protected]>

src/model.ts

@@ -361,7 +361,10 @@ export class Model extends EventBus<any> implements CommandDispatcher {
    */
   private checkDispatchAllowed(command: Command): DispatchResult {
     const results = this.handlers.map((handler) => handler.allowDispatch(command));
-    return new DispatchResult(results.flat());
+    if (results.some((r) => r !== CommandResult.Success)) {
+      return new DispatchResult(results.flat());
+    }
+    return DispatchResult.Success;
   }
 
   private finalize() {