Table "fees": add missing foreign key on "account_row_id"

The MariaDB table fees is probably missing a foreign key.

Current definition:

CREATE TABLE `fees` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  `account_row_id` int(10) unsigned DEFAULT NULL,
  `user_id` int(10) unsigned NOT NULL,
  `year` int(11) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `fees_user_id_foreign` (`user_id`),
  CONSTRAINT `fees_user_id_foreign` FOREIGN KEY (`user_id`) REFERENCES `users` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

Definition of the destination:

CREATE TABLE `account_rows` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  `movement_id` int(10) unsigned DEFAULT NULL,
  `account_id` int(10) unsigned NOT NULL,
  `user_id` int(10) unsigned NOT NULL DEFAULT 0,
  `section_id` int(10) unsigned NOT NULL DEFAULT 0,
  `amount_in` decimal(10,2) NOT NULL DEFAULT 0.00,
  `amount_out` decimal(10,2) NOT NULL DEFAULT 0.00,
  `notes` text NOT NULL,
  PRIMARY KEY (`id`),
  KEY `account_rows_movement_id_foreign` (`movement_id`),
  CONSTRAINT `account_rows_movement_id_foreign` FOREIGN KEY (`movement_id`) REFERENCES `movements` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

The table fees is probably missing a foreign key, like this one:

ALTER TABLE fees ADD CONSTRAINT `fees_account_row_id_foreign` FOREIGN KEY (`account_row_id`) REFERENCES `account_rows`(`id`);

Let's add a migration script to add that specific foreign key.

Migration scripts are here:

https://gitlab.com/ItalianLinuxSociety/ilsmanager/-/tree/master/database/migrations?ref_type=heads