Prevent upscaling images in canvas mode

[swissspidy]

• Adds e2e tests focusing on this part
• Improves wording in preferences modal

Fixes #487

[github-actions[bot]]

Size Change: +100 B (0%)

Total Size: 3.04 MB

ℹ️ View Unchanged

| Filename | Size | Change | | :--- | :---: | :---: | | `build/100.js` | 87.3 kB | 0 B | | `build/534.js` | 7.6 kB | 0 B | | `build/699.js` | 2.36 MB | 0 B | | `build/blurhash.worker.js` | 3.19 kB | 0 B | | `build/canvas.worker.js` | 2.8 kB | +35 B (+1.26%) | | `build/chunk-ffmpeg.js` | 5.9 kB | 0 B | | `build/chunk-selfie-segmentation.js` | 16.3 kB | 0 B | | `build/dominant-color.worker.js` | 4.46 kB | 0 B | | `build/ffmpeg.js` | 1.1 kB | 0 B | | `build/heif.worker.js` | 424 kB | 0 B | | `build/media-experiments-blocks-rtl.css` | 298 B | 0 B | | `build/media-experiments-blocks.css` | 297 B | 0 B | | `build/media-experiments-rtl.css` | 764 B | 0 B | | `build/media-experiments.css` | 765 B | 0 B | | `build/media-experiments.js` | 63.7 kB | +36 B (+0.06%) | | `build/pdf.js` | 516 B | 0 B | | `build/subtitles.js` | 864 B | 0 B | | `build/upload-requests-modal-rtl.css` | 267 B | 0 B | | `build/upload-requests-modal.css` | 268 B | 0 B | | `build/upload-requests-modal.js` | 801 B | 0 B | | `build/view-upload-request-view-rtl.css` | 714 B | 0 B | | `build/view-upload-request-view.css` | 716 B | 0 B | | `build/view-upload-request.js` | 16.6 kB | +29 B (+0.17%) | | `build/vips.worker.js` | 42.4 kB | 0 B |

_{compressed-size-action}