fix: catch regex FormatException and show a corresponding error message (#573)

* add error message

* restore and reformat

* update localization and comments

* chore: reformat files

lib/l10n/intl_en.arb

@@ -128,6 +128,9 @@
   "replaceAll": "Replace all",
   "regex": "Regex",
   "caseSensitive": "Case sensitive",
+  "regexError": "Regex Error",
+  "noFindResult": "No result",
+  "emptySearchBoxHint": "Enter a pattern",
   "uploadImage": "Upload Image",
   "urlImage": "URL Image",
   "incorrectLink": "Incorrect Link",

lib/l10n/intl_zh_CN.arb

@@ -128,6 +128,9 @@
   "replaceAll": "替换全部",
   "regex": "正则表达式",
   "caseSensitive": "区分大小写",
+  "regexError": "正则错误",
+  "noFindResult": "无匹配项",
+  "emptySearchBoxHint": "输入查找内容",
   "uploadImage": "上传图片",
   "urlImage": "网络图片",
   "incorrectLink": "链接错误",

lib/l10n/intl_zh_TW.arb

@@ -128,6 +128,9 @@
   "replaceAll": "取代全部",
   "regex": "正規表示式",
   "caseSensitive": "區分大小寫",
+  "regexError": "正規錯誤",
+  "noFindResult": "無相符項",
+  "emptySearchBoxHint": "鍵入尋找内容",
   "uploadImage": "上載圖片",
   "urlImage": "網路圖片",
   "incorrectLink": "連結錯誤",