Qt Design Studio WebAssembly Viewer examples does not fit typical screens

The QML for the examples at the Design Viewer page (https://qt-webassembly.io/designviewer/) use hardcoded sizes. The sizes are quite large, which causes the examples to require scrolling on standard screens such as 15-inch laptops.

A possible solution is to add a fit-to-viewport mode:

• Normally, html canvas geometry is set to fit the viewport (or a sub-section of the page, as desired). The geometry then propagates to QScreen and to the "full-screen" QWindow. QWindow content adjusts to the window size using layouts. Note that geometry is in CSS pixels / device independent pixels, which means that high-DPI support does not factor into this.
• For fit-to-viewport, the html canvas could be sized to contain the the content, and then scaled using CSS scaling to fit the viewport. The QScreen takes canvas geometry and contains a FullScreen QWindow as before.
• Quick-fix: scale the canvas to ~50%, since the existing examples are close to 2x