refactoring: reduced cyclomatic complexity for function assign_first_possible_offer_to_student
refactoring: reduced cyclomatic complexity for function assign_first_possible_offer_to_student

uclouvain/osis,uclouvain/osis,uclouvain/osis_louvain,uclouvain/OSIS-Louvain,uclouvain/osis_louvain,uclouvain/osis_louvain,uclouvain/osis,uclouvain/OSIS-Louvain,uclouvain/osis,uclouvain/OSIS-Louvain