Bug 34445: Set default budget in addorderiso2709.pl

Bug 34445: Set default budget in addorderiso2709.pl

This patch allows the default budget to be used as a fallback if no budget is selected. Currently the default budget is set using lines 129-133 but then is never used.

QA follow-up:
- perl tidied
- budget_codes changed to budget_ids for consistency

Test plan:
1) Apply patch
2) restart_all
3) Follow the steps from the bug description
4) Order lines should be added properly

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
[EDIT] Rearranged comments
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>