add element icons

backend/app/Element/Element.php

@@ -10,6 +10,7 @@ class Element
         private int $id,
         private string $title,
         private string $description,
+        private ?string $iconImageUrl,
         private string $richText,
         private ?string $pdfPath,
         private ?string $youtubeUrl,
@@ -33,6 +34,11 @@ class Element
         return $this->description;
     }
 
+    public function getIconImageUrl(): ?string
+    {
+        return $this->iconImageUrl;
+    }
+
     public function getRichText(): string
     {
         return $this->richText;