fix: board crashes with empty string favicon (#2192)

packages/common/src/string.ts

@@ -1,3 +1,7 @@
 export const capitalize = <T extends string>(str: T) => {
   return (str.charAt(0).toUpperCase() + str.slice(1)) as Capitalize<T>;
 };
+
+export const isNullOrWhitespace = (value: string | null): value is null => {
+  return value == null || value.trim() === "";
+};