Fixed numerous bugs and wrong/bad querys in db_interface
Fixed numerous bugs and wrong/bad querys in db_interface

Fixed an issue where the array_merge was not working as intended as
it does not merge duplicate keys, have to use two foreach loops

Fixed function is_candidate which had the wrong parameters

Fixed querys that check if a nominee is a candidate/nominee/member
where the EXISTS queries were incorrect

CS-CLUB/elections-website,CS-CLUB/elections-website