Migrate desktop_photo_search to top level (#1002)

desktop_photo_search/material/lib/src/unsplash/position.dart

@@ -0,0 +1,35 @@
+// Copyright 2019 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:convert';
+
+import 'package:built_value/built_value.dart';
+import 'package:built_value/serializer.dart';
+
+import '../serializers.dart';
+
+part 'position.g.dart';
+
+abstract class Position implements Built<Position, PositionBuilder> {
+  factory Position([void Function(PositionBuilder)? updates]) = _$Position;
+
+  Position._();
+
+  @BuiltValueField(wireName: 'latitude')
+  double get latitude;
+
+  @BuiltValueField(wireName: 'longitude')
+  double get longitude;
+
+  String toJson() {
+    return json.encode(serializers.serializeWith(Position.serializer, this));
+  }
+
+  static Position? fromJson(String jsonString) {
+    return serializers.deserializeWith(
+        Position.serializer, json.decode(jsonString));
+  }
+
+  static Serializer<Position> get serializer => _$positionSerializer;
+}