fix(i18n): reuse translation strings from WindowedFrame

字母表排序页面中，关机与控制中心两个按钮的提示文案应当直接复用小窗口
启动器的文案，不需要重新重复翻译。

Log:
Issue: linuxdeepin/developer-center#6520

qml/AlphabetCategory.qml

@@ -93,7 +93,7 @@ ColumnLayout {
             icon.name: "shutdown"
             ToolTip.visible: hovered
             ToolTip.delay: 1000
-            ToolTip.text: qsTr("Power")
+            ToolTip.text: qsTranslate("WindowedFrame", "Power")
             onClicked: {
                 DesktopIntegration.openShutdownScreen();
             }
@@ -103,7 +103,7 @@ ColumnLayout {
             icon.name: "setting"
             ToolTip.visible: hovered
             ToolTip.delay: 1000
-            ToolTip.text: qsTr("Control Center")
+            ToolTip.text: qsTranslate("WindowedFrame", "Control Center")
             onClicked: {
                 DesktopIntegration.openSystemSettings();
             }