feat: Invoice -> Zahlungen buchen

ajax/invoices/addPayment.php

ajax/invoices/list.php

ajax/invoices/temporary/post.php

bin/backend/classes/Invoices.js

bin/backend/controls/panels/Journal.css

bin/backend/controls/panels/Journal.js

bin/backend/controls/panels/TemporaryInvoice.js

bin/backend/controls/panels/TemporaryInvoices.js

bin/backend/controls/panels/payments/AddPayment.html

bin/backend/controls/panels/payments/AddPayment.js

bin/backend/controls/panels/payments/AddPaymentWindow.js

bin/backend/downloadInvoice.php

database.xml

locale.xml

src/QUI/ERP/Accounting/Invoice/Handler.php

src/QUI/ERP/Accounting/Invoice/Invoice.php

src/QUI/ERP/Accounting/Invoice/TemporaryInvoice.php