Bug 11759: Batch checkout - prepare the ground

Bug 11759: Batch checkout - prepare the ground

This patch does not introduce any changes.
It prepares the circulation script to accept several barcodes in
parameter.
A loop is done on all barcodes (until now, only 1) to generate a
structure to sent to the template.
At the end, only the first generated data is sent.

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>