Make zoom direction in animation preview and hitbox editor consistent with the rest of the editor. (#2056)

Don't show the rest in the changelog:
* Inverse zoom in preview animation and hitbox editor.
* Make consistent with zoom direction in scene editor.
* Prettier

newIDE/app/src/ResourcesList/ResourcePreview/ImagePreview.js

@@ -209,7 +209,7 @@ export default class ImagePreview extends React.Component<Props, State> {
                   const { deltaY } = event;
                   //TODO: Use KeyboardShortcuts
                   if (event.metaKey || event.ctrlKey) {
-                    this._zoomBy(deltaY / 500);
+                    this._zoomBy(-deltaY / 500);
                     event.preventDefault();
                     event.stopPropagation();
                   } else {