fix: 修复聊天系统编译错误

- 修复 WebSocketManager/SocketIOClient 函数缩进错误
- 重命名 is_connected() 避免与 Object 基类冲突
- 修复 tscn 文件多余前导空格
- 修复测试文件 GUT 断言函数调用
- 添加 GUT 测试框架

addons/gut/dynamic_gdscript.gd

@@ -0,0 +1,33 @@
+@tool
+var default_script_name_no_extension = 'gut_dynamic_script'
+var default_script_resource_path = 'res://addons/gut/not_a_real_file/'
+var default_script_extension = "gd"
+
+var _created_script_count = 0
+
+
+# Creates a loaded script from the passed in source.  This loaded script is
+# returned unless there is an error.  When an error occcurs the error number
+# is returned instead.
+func create_script_from_source(source, override_path=null):
+	_created_script_count += 1
+	var r_path = str(default_script_resource_path,
+		default_script_name_no_extension, '_', _created_script_count, ".",
+		default_script_extension)
+
+	if(override_path != null):
+		r_path = override_path
+
+	var DynamicScript = GDScript.new()
+	DynamicScript.source_code = source.dedent()
+	# The resource_path must be unique or Godot thinks it is trying
+	# to load something it has already loaded and generates an error like
+	# ERROR: Another resource is loaded from path 'workaround for godot
+	# issue #65263' (possible cyclic resource inclusion).
+	DynamicScript.resource_path = r_path
+	var result = DynamicScript.reload()
+	if(result != OK):
+		DynamicScript = result
+
+	return DynamicScript
+