thumbhash improvements

mobile/lib/widgets/common/thumbhash.dart

@@ -0,0 +1,23 @@
+import 'dart:convert';
+
+import 'package:flutter/widgets.dart';
+import 'package:thumbhash/thumbhash.dart' as thumbhash;
+
+class Thumbhash extends StatelessWidget {
+  final String blurhash;
+  final BoxFit fit;
+
+  const Thumbhash({
+    required this.blurhash,
+    this.fit = BoxFit.cover,
+    super.key,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Image.memory(
+      thumbhash.rgbaToBmp(thumbhash.thumbHashToRGBA(base64.decode(blurhash))),
+      fit: fit,
+    );
+  }
+}