[cron-job] allow a cronjob to pass data from one execution to another

When a cronjob is executed, it may return an array of data.

This data will be passed as parameter on the next execution

src/Bundle/ChillMainBundle/Cron/CronJobInterface.php

@@ -19,5 +19,13 @@ interface CronJobInterface
 
     public function getKey(): string;
 
-    public function run(): void;
+    /**
+     * Execute the cronjob
+     *
+     * If data is returned, this data is passed as argument on the next execution
+     *
+     * @param array $lastExecutionData the data which was returned from the previous execution
+     * @return array|null optionally return an array with the same data than the previous execution
+     */
+    public function run(array $lastExecutionData): null|array;
 }