Refactor entities and codebase for native property usage

- Replaced getters/setters with direct property access across entities and repositories.
- Added and configured `martin-georgiev/postgresql-for-doctrine` for PostgreSQL enhancements.
- Updated Doctrine configuration with types, mappings, and JSONB query functions.
- Removed unused `EliminationService` and related YAML configurations.

migrations/Version20241229202155.php

@@ -7,9 +7,6 @@ namespace DoctrineMigrations;
 use Doctrine\DBAL\Schema\Schema;
 use Doctrine\Migrations\AbstractMigration;
 
-/**
- * Auto-generated Migration: Please modify to your needs!
- */
 final class Version20241229202155 extends AbstractMigration
 {
     public function getDescription(): string
@@ -19,13 +16,11 @@ final class Version20241229202155 extends AbstractMigration
 
     public function up(Schema $schema): void
     {
-        // this up() migration is auto-generated, please modify it to your needs
         $this->addSql('CREATE UNIQUE INDEX UNIQ_A29DA1B891BD8781853CD175 ON correction (candidate_id, quiz_id)');
     }
 
     public function down(Schema $schema): void
     {
-        // this down() migration is auto-generated, please modify it to your needs
         $this->addSql('CREATE SCHEMA public');
         $this->addSql('DROP INDEX UNIQ_A29DA1B891BD8781853CD175');
     }