Bug 21604: Fix add/edit fund/budget

Bug 21604: Fix add/edit fund/budget

[Strict SQL modes context]

For insert aqbudgetperiods:
Incorrect integer value: '' for column 'budget_period_id'

For insert/update aqbudgets
Incorrect integer value: '' for column 'budget_owner_id'
Incorrect decimal value: '' for column 'budget_encumb'

Test plan:
Add/edit budgets and funds

A good example of why we should use Koha::Object for all our objects

Signed-off-by: Pierre-Marc Thibault <pierre-marc.thibault@inLibro.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>