Scorer: Add a "Judge Error" verdict

[jonathanirvings]

Currently only AC, WA, and partial points verdict are supported in https://tcframe.toki.id/docs/api/helpers/#verdict-format.

Sometimes, scorer should also produce a Judge Error verdict when an obvious judge's mistake is spotted (e.g., when contestant found a valid solution that is better than the judge's solution). The distinction to use this verdict is critical to spot issues during development (and sometimes, during contest).