✨ add Uri extension (#18)

lib/qs_dart.dart

@@ -9,4 +9,5 @@ export 'src/methods.dart' show decode, encode;
 export 'src/models/decode_options.dart';
 export 'src/models/encode_options.dart';
 export 'src/models/undefined.dart';
+export 'src/uri.dart';
 export 'src/qs.dart';

lib/src/uri.dart

@@ -0,0 +1,19 @@
+import 'package:qs_dart/qs_dart.dart';
+
+extension UriExtension on Uri {
+  /// The URI query split into a map.
+  /// Providing custom [options] will override the default behavior.
+  Map<String, dynamic> queryParametersQs([
+    DecodeOptions options = const DecodeOptions(),
+  ]) =>
+      query.isNotEmpty ? QS.decode(query, options) : const <String, dynamic>{};
+
+  /// The normalized string representation of the URI.
+  /// Providing custom [options] will override the default behavior.
+  String toStringQs([EncodeOptions options = const EncodeOptions()]) => replace(
+        query: queryParameters.isNotEmpty
+            ? QS.encode(queryParameters, options)
+            : null,
+        queryParameters: null,
+      ).toString();
+}