fix: global variable key repeat & value type (#2540)

packages/web/i18n/en/common.json

@@ -914,6 +914,7 @@
         "add option": "Add option",
         "input type": "Text",
         "key": "Variable key",
+        "key already exists": "Key already exist",
         "key is required": "Variable key is required",
         "select type": "Dropdown single select",
         "text max length": "Maximum length",

packages/web/i18n/zh/common.json

@@ -914,6 +914,7 @@
         "add option": "添加选项",
         "input type": "文本",
         "key": "变量 key",
+        "key already exists": "Key 已经存在",
         "key is required": "变量 key 是必须的",
         "select type": "下拉单选",
         "text max length": "最大长度",