Bug 7615 - Give option to use description for homebranch/holding branch in label...

Bug 7615 - Give option to use description for homebranch/holding branch in label creator instead of the branchcode

This patch adds the ability to print the name of the item's homebranch on labels

Thanks to Shane Sammons <ssammons-at-npelem.com> for the modified SQL SELECT statement.

Document Manager: The documentation will need to be updated to reflect the added field 'branchname' to the list
of available fields for label printing.

To test:

1. Create a new label layout or modify an existing one to include 'branchname'
2. Create a new label batch or using an existing one, export the batch.
3. Verify that the resulting labels contain the home branch name for the respective items.

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Tested with the plan - works

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>