Bug 24474: (follow-up) Add LOST_FOUND logic to Koha::Account::pay

Bug 24474: (follow-up) Add LOST_FOUND logic to Koha::Account::pay

This patch adds the same updated logic as found in
Koha::Account::Line->apply to handle LOST_FOUND credits being applied
against their associated LOST debit.

Currently a 'LOST_FOUND' credit is never created via the pay method and
so the additional test will always pass, but the addition here accounts
for possible future uses.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>