feat: mail entity download

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

shared/lib/Resource/BinaryResource.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: Sebastian Krupinski <krupinski01@gmail.com>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace KTXF\Resource;
+
+/**
+ * Carries file-like binary content metadata and a byte stream.
+ */
+final class BinaryResource
+{
+    public function __construct(
+        private readonly string $filename,
+        private readonly string $mimeType,
+        private readonly \Generator $stream,
+    ) {}
+
+    public function filename(): string
+    {
+        return $this->filename;
+    }
+
+    public function mimeType(): string
+    {
+        return $this->mimeType;
+    }
+
+    public function stream(): \Generator
+    {
+        return $this->stream;
+    }
+}