feat: Implement registration feature and update database service

This commit creates new methods for the authentication system, especially the user registration feature. The update also validates input data and checks if a user already exists in the database. It modifies the application entry point to include the updated user registration route and provides updates to the database service to include user-related functions. The MariaDB collation was also updated in the database schema script to support unicode.

.env.exemple

@@ -2,6 +2,9 @@ APP_PORT: 3000
 DEBUG: true
 CONTEXT: dev
 
+HASH_SECRET: ''
+JWT_SECRET: ''
+
 MYSQL_PORT: 3434
 MYSQL_HOST: 'localhost'
 MYSQL_USERNAME: 'apdbqixmwnsesdj'