refien dart/swfit dir structure

Author: chaokunyang

dart/packages/fory/lib/src/serializer/scalar_serializers.dart

@@ -22,7 +22,7 @@ import 'dart:typed_data';
 import 'package:fory/src/context/read_context.dart';
 import 'package:fory/src/context/write_context.dart';
 import 'package:fory/src/serializer/serializer.dart';
-import 'package:fory/src/string_encoding.dart';
+import 'package:fory/src/util/string_util.dart';
 import 'package:fory/src/types/decimal.dart';
 
 // The small form reserves the low header bit to distinguish small/big

…ckages/fory/lib/src/string_encoding.dart …kages/fory/lib/src/util/string_util.dartdart/packages/fory/lib/src/string_encoding.dart renamed to dart/packages/fory/lib/src/util/string_util.dart dart/packages/fory/lib/src/string_encoding.dart renamed to dart/packages/fory/lib/src/util/string_util.dart

@@ -18,7 +18,7 @@
  */
 
 import 'package:fory/src/buffer.dart';
-import 'package:fory/src/string_encoding.dart';
+import 'package:fory/src/util/string_util.dart';
 import 'package:test/test.dart';
 
 void main() {

dart/packages/fory/test/string_encoding_test.dart

@@ -21,7 +21,7 @@ import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:fory/fory.dart';
-import 'package:fory/src/string_encoding.dart';
+import 'package:fory/src/util/string_util.dart';
 import 'package:test/test.dart';
 
 void main() {

dart/packages/fory/test/string_serializer_test.dart

@@ -35,8 +35,7 @@ let package = Package(
         .target(
             name: "Fory",
             dependencies: ["ForyMacro"],
-            path: "Sources",
-            exclude: ["ForyMacro"]
+            path: "Sources/Fory"
         ),
         .executableTarget(
             name: "ForyXlangTests",