Use QbMapper to replace the Mapper removed in nextcloud version 26.0.0

[fcki1984]

by chatgpt.

[devnoname120]

@maurerle You may consider adding https://github.com/nextcloud/server codestyle commands to auto fix formatting.

See:

• https://github.com/nextcloud/server/blob/master/.editorconfig
• https://github.com/nextcloud/server/blob/ba867b6257941a01e0ac3591114fbd660499ee8d/composer.json#L47-L49
• https://github.com/nextcloud/server/blob/master/.php-cs-fixer.dist.php
• https://github.com/nextcloud/server/blob/ba867b6257941a01e0ac3591114fbd660499ee8d/.pre-commit-config.yaml
• https://github.com/nextcloud/server/blob/master/.github/workflows/lint-php.yml
• https://github.com/nextcloud/server/blob/master/.github/workflows/lint-php-cs.yml

[devnoname120]

@fcki1984 Bump

[devnoname120]

Superseded by https://github.com/e-alfred/epubreader/pull/50.