[FIX] account: qr_code_urls bug in report invoice template

To reproduce:

1) activate qr code on invoices
2) print an invoice with a qr code
3) print a followup letter, and attach the printed invoice

-> error due to missing 'qr_code_urls' variable in invoice template

This can happen with any report calling this template, thus we decided to set the qr_code_urls
inside the `report_invoice_document` template directly, so we never need to set it again in _get_report_values()
This allows to remove the following report classes (done in master due to stable policy)
- `ReportInvoiceWithoutPayment`
- `ReportInvoiceWithPayment`
- `PosInvoiceReport` (not even used anywhere)

closes odoo/odoo#106448

Signed-off-by: Brice Bartoletti (bib) <bib@odoo.com>