Add scramble image viewer with show/hide control

[coder13]

Users asked for visual scramble diagrams that can be shown or hidden.

Feedback source:

• Add an image of the scramble that you can hide/show using a button.
• Draw scramble for all events.
• There is only 3x3 but we need another event.

Acceptance ideas:

• Add a show/hide control for scramble visualization.
• Start with supported events and fail gracefully for unsupported events.
• Keep scramble text available even when the image is hidden.
• Consider how this interacts with completed solve review/history.