Allow widgets to be added to canvas

### What is the problem or limitation you are having?

For a non-linear graphic editor, I need to add normal widgets to the canvas. In the Qt program, widgets in the canvas have more possibilities. Like clicking and moving. But canvas special widgets either don't have these facilities or we didn't find them...

### Describe the solution you'd like

context.append(Button , Box, ....)

### Describe alternatives you've considered

Rect.on_press = .....

### Additional context

_No response_

Start by reviewing the canvas API around the proposed context.append(Button, Box, ...) usage and the Rect.on_press alternative. Compare the requested behavior with the Qt canvas example linked in the issue. Done means normal widgets can be added to the canvas and support the stated clicking and moving interactions.

Written by the indexing model from the issue text.