feat: Translate frontend/src/i18n/en.json in zh_CN

99% of minimum 50% translated source file: 'frontend/src/i18n/en.json'
on 'zh_CN'.

Sync of partially translated files: 
untranslated content is included with an empty translation 
or source language content depending on file format

frontend/src/i18n/zh-cn.json

@@ -84,7 +84,7 @@
     "showingRows": "正在显示 {count} 行",
     "columnSeparator": "列分隔符",
     "csvSeparators": {
-      "comma": "Comma (,)",
+      "comma": "逗号 (,)",
       "semicolon": "Semicolon (;)",
       "both": "Both (,) and (;)"
     }