refactor(mobile): widgets (#9291)

* refactor(mobile): widgets

* update

mobile/lib/widgets/common/fade_in_placeholder_image.dart

@@ -0,0 +1,35 @@
+import 'package:flutter/material.dart';
+import 'package:immich_mobile/widgets/common/transparent_image.dart';
+
+class FadeInPlaceholderImage extends StatelessWidget {
+  final Widget placeholder;
+  final ImageProvider image;
+  final Duration duration;
+  final BoxFit fit;
+
+  const FadeInPlaceholderImage({
+    super.key,
+    required this.placeholder,
+    required this.image,
+    this.duration = const Duration(milliseconds: 100),
+    this.fit = BoxFit.cover,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return SizedBox.expand(
+      child: Stack(
+        fit: StackFit.expand,
+        children: [
+          placeholder,
+          FadeInImage(
+            fadeInDuration: duration,
+            image: image,
+            fit: fit,
+            placeholder: MemoryImage(kTransparentImage),
+          ),
+        ],
+      ),
+    );
+  }
+}