test: add readline test for escape sequence

Tests do not cover a small piece of code in
lib/internal/readline/utils.js for consuming an escape sequence.
This adds a minimal test to cover the code.

Refs: https://coverage.nodejs.org/coverage-0848f56cb3943209/lib/internal/readline/utils.js.html#L327

PR-URL: #34952
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>

test/parallel/test-readline-keys.js

@@ -114,6 +114,9 @@ addTest('\x1b\x1b\x1b', [
   { name: 'escape', sequence: '\x1b\x1b\x1b', meta: true },
 ]);
 
+// Escape sequence
+addTest('\x1b]', [{ name: undefined, sequence: '\x1B]', meta: true }]);
+
 // Control keys
 addTest('\x01\x0b\x10', [
   { name: 'a', sequence: '\x01', ctrl: true },