feat(#23): use landlord profiles in PDFs

frontend/src/app/services/http-error-message.ts

@@ -0,0 +1,11 @@
+export function httpErrorMessage(error: unknown, fallback: string): string {
+  return typeof error === 'object' &&
+    error !== null &&
+    'error' in error &&
+    typeof error.error === 'object' &&
+    error.error !== null &&
+    'message' in error.error &&
+    typeof error.error.message === 'string'
+    ? error.error.message
+    : fallback;
+}