Pressing the space key doesn't select or deselect focused packs in the resource pack and data pack menus

The Bug:

Pressing the space key doesn't select or deselect focused packs in the resource pack and data pack menus.

In the resource pack and data pack screens, a pack that's focused with the keyboard can be moved between the lists by pressing the enter key, but pressing the space key does nothing. The space key does the same as the enter key on every other focused button and list entry, therefore introducing an inconsistency.

Steps to Reproduce:

1. Open the "Resource Packs" screen.

2. Press the tab key until a pack in the "Available" list is focused.

3. Now press the space key.

4. Observe if the pack moves to the "Selected" list.

Observed Behavior:

Pressing the space key on a focused pack doesn't move it.

Expected Behavior:

The pack would move lists, just like it does when pressing the enter key.