fix(format-bad-encoding): make method work with undefined values

Author: bodintsov

src/app/shared/helpers/format-bad-encoding.helper.ts

@@ -1,3 +1,4 @@
 export function replaceBadEncodedChars(text: string) {
+  if (!text) return '';
   return text.replace(/&amp;/gi, '&').replace(/&lt;/gi, '<').replace(/&gt;/gi, '>');
 }