feat: remind teamers of open questionnaires on the dashboard

src/Config/QuestionnaireCatalog.php

@@ -51,6 +51,20 @@ class QuestionnaireCatalog
     ) {
     }
 
+    /**
+     * The services.yaml parameter questionnaire_go_live as a date: the teamer questionnaire is
+     * offered for assignments ending on or after it, and to nobody while it is null.
+     */
+    public static function parseGoLive(?string $goLive): ?\DateTimeImmutable
+    {
+        if (null === $goLive) {
+            return null;
+        }
+
+        return \DateTimeImmutable::createFromFormat('!Y-m-d', $goLive)
+            ?: throw new \InvalidArgumentException(sprintf('questionnaire_go_live "%s" is not a Y-m-d date', $goLive));
+    }
+
     /**
      * @param int|null $version null for the current version
      */