Implemented the upload status snackbar on the home screen, created the [DistinctStreamTransformer] and refactored how screens decide when to show a snackbar

test/src/utils_test.dart

@@ -0,0 +1,15 @@
+import 'dart:async';
+
+import 'package:do_more/src/utils.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+main() {
+  group('DistinctStreamTransformer', () {
+    test('should only emit non repeated elements', () {
+      final stream = Stream.fromIterable([1, 1, 1, 2, 2, 2, 1, 1, 1, 1]);
+      final transformedStream = stream.transform(DistinctStreamTransformer());
+
+      expect(transformedStream.toList(), completion(equals([1, 2, 1])));
+    });
+  });
+}