- Refactor to use services and dependency injection.
- Rewrite QR code generation to use endroid/qr-code (previous library has been deprecated).
- Add support for specific pixel sizes in the size parameter.
- Smarter handling of default parameter values.

- Installing phpDocumentor via Composer was causing dependency conflicts; this offers a more self-contained approach to using the tool.

Add platform config for target PHP version so that suitable dependencies are installed even if composer is run with a newer PHP version. (#1030)

- Only used in development mode; provides more detailed debugging details.