完善翻译，添加翻译缺失检查工具

package.json

@@ -1,12 +1,13 @@
 {
   "name": "hydrooj",
-  "version": "2.7.2",
+  "version": "2.7.3",
   "main": "hydro/loader.ts",
   "repository": "https://github.com/hydro-dev/Hydro.git",
   "author": "masnn",
   "license": "GPL-3.0-only",
   "dependencies": {
     "@hydrooj/markdown-it-katex": "^2.1.1",
+    "@types/lru-cache": "^5.1.0",
     "adm-zip": "^0.4.16",
     "ansi_up": "^4.0.4",
     "detect-browser": "^5.1.1",
@@ -17,6 +18,7 @@
     "koa-router": "^8.0.8",
     "koa-static-cache": "^5.1.3",
     "lodash": "^4.17.19",
+    "lru-cache": "^6.0.0",
     "markdown-it": "^11.0.0",
     "markdown-it-anchor": "^5.3.0",
     "markdown-it-container": "^3.0.0",