refactor: modify datasource extra config text

frontend/src/i18n/en.json

@@ -220,7 +220,7 @@
       "database": "Database",
       "connect_mode": "Connect Mode",
       "service_name": "Service Name",
-      "extra_jdbc": "Extra JDBC String",
+      "extra_jdbc": "Extra Config",
       "schema": "Schema",
       "get_schema": "Get Schema",
       "file": "File",

frontend/src/i18n/zh-CN.json

@@ -220,7 +220,7 @@
       "database": "数据库",
       "connect_mode": "连接方式",
       "service_name": "服务名",
-      "extra_jdbc": "额外的 JDBC 连接字符串",
+      "extra_jdbc": "额外的数据库连接配置",
       "schema": "模式",
       "get_schema": "获取模式",
       "file": "文件",