feat: Calc, ERP Artikel und Artikel Liste, Grundklassen umgesetzt

locale.xml

src/QUI/ERP/Accounting/Article.php

src/QUI/ERP/Accounting/ArticleInterface.php

src/QUI/ERP/Accounting/ArticleList.php

src/QUI/ERP/Accounting/ArticleListUnique.php

src/QUI/ERP/Accounting/Calc.php

src/QUI/ERP/Defaults.php

src/QUI/ERP/Exception.php

src/QUI/ERP/Money/Price.php

src/QUI/ERP/Packages/Installer.php

src/QUI/ERP/User.php

src/QUI/ERP/Utils/User.php