fix(@vben/locales): 修复锁屏弹窗按钮文案歧义 (#8211)

锁屏设置弹窗(lock-screen-modal)的确认按钮作用是输入密码后锁定屏幕，
但按钮文案 i18n key `ui.widgets.lockScreen.screenButton` 原值为「解锁」/「Unlock」，
与弹窗标题「锁定屏幕」及实际动作矛盾，存在歧义。

- zh-CN: 「解锁」->「锁定」
- en-US: 「Unlock」->「Lock」

(同段另有 `unlock` key 值「点击解锁」，用于已锁定后的全屏解锁界面，语义正确，保持不变)

packages/locales/src/langs/en-US/ui.json

@@ -149,7 +149,7 @@
     },
     "lockScreen": {
       "title": "Lock Screen",
-      "screenButton": "Unlock",
+      "screenButton": "Lock",
       "password": "Password",
       "placeholder": "Please enter password",
       "unlock": "Click to unlock",

packages/locales/src/langs/zh-CN/ui.json

@@ -149,7 +149,7 @@
     },
     "lockScreen": {
       "title": "锁定屏幕",
-      "screenButton": "解锁",
+      "screenButton": "锁定",
       "password": "密码",
       "placeholder": "请输入锁屏密码",
       "unlock": "点击解锁",