User story
If a user wants to print a URL onto business cards or poster they may want a QR code in addition to a short URL. This could happen automatically.
Acceptance Criteria
- code goes in the UrlShortener extension
- all QR code functionality should be behind a feature flag ($wgUrlShortenerEnableQrCode)
- add a "Download QR code" link to the toolbox which will download an SVG
- Use endroid/qr-code to generate the QR codes server-side
- It was noted that it's cheaper to send the QR code than the JavaScript module to generate it
- Requires security review and addition to mediawiki/libs repo (T339389)
- if the URL is very long (>= 200 bytes, controlled by $wgUrlShortenerQrCodeShortenLimit), generate a short URL first so that the QR code isn't too high of density
- Add a qrcode boolean option to the shortenurl API endpoint.