Fix escaping and unescaping strings with backslashes

Author: pklaschka

example/locales/de.json

@@ -1,6 +1,8 @@
 {
   "Hello world!": "Hallo Welt!",
   "Lazy term": "Fauler Begriff",
-  "This text contains {0} \\{} curly braces and \\\\{\\{}}\\{0}.": "Dieser Text enthält {0} \\{} geschweifte Klammern und \\\\{\\{}}\\{0}.",
-  "Untranslated text": ""
+  "Untranslated text": "",
+  "Unknown Error": "",
+  "An unexpected error occurred while processing your request.": "",
+  "This text contains {0} \\{} curly braces and \\\\\\{\\{}}\\{0}.": "Dieser Text enthält {0} \\{} geschweifte Klammern und \\\\\\{\\{}}\\{0}."
 }

example/locales/en.json

@@ -1,6 +1,8 @@
 {
   "Hello world!": "Hello world!",
   "Lazy term": "Lazy term",
-  "This text contains {0} \\{} curly braces and \\\\{\\{}}\\{0}.": "This text contains {0} \\{} curly braces and \\\\{\\{}}\\{0}.",
-  "Untranslated text": "Untranslated text"
+  "Untranslated text": "Untranslated text",
+  "Unknown Error": "Unknown Error",
+  "An unexpected error occurred while processing your request.": "An unexpected error occurred while processing your request.",
+  "This text contains {0} \\{} curly braces and \\\\\\{\\{}}\\{0}.": "This text contains {0} \\{} curly braces and \\\\\\{\\{}}\\{0}."
 }

lib/common/unescapeKey.ts

@@ -1,3 +1,3 @@
 export function unescapeKey(key: string): string {
-  return key.replaceAll(/\\{/g, "{");
+  return key.replaceAll(/\\{/g, "{").replaceAll(/\\\\/g, "\\");
 }