Fix demo page

demo/src/dbp-qr-code-scanner-demo-activity.js

demo/src/styles.js

demo/yarn.lock

packages/common/dbp-common-demo.js

...view/src/dbp-knowledge-base-web-page-element-view-demo.js

packages/matomo/src/dbp-matomo-demo.js

packages/notification/src/dbp-notification-demo.js

packages/person-profile/src/dbp-person-profile-demo.js

packages/person-select/src/dbp-person-select-demo.js

packages/qr-code-scanner/src/dbp-qr-code-scanner-demo.js