Feat: Implement contract generation and up-/downloading

src/Entity/Embeddable/Address.php

@@ -52,6 +52,11 @@ class Address
         }
     }
 
+    public function __toString()
+    {
+        return sprintf('%s, %s %s', $this->street, $this->postCode, $this->city);
+    }
+
     public function toPayload(): array
     {
         return [