BSG now considers GP coin to be a currency.
Commit 4788f6b407 (diff-d1c96eaf446b0afaf70c62191c7a688471fca50c) already added GP coin to the `Money` enum, but it needs to be added to `PaymentHelper.isMoneyTpl()` to prevent it from being filtered by the barter filter as with other money offers.
See attached screenshots for a demonstration of SPT vs live behavior.
Reviewed-on: https://dev.sp-tarkov.com/SPT/Server/pulls/363
Co-authored-by: IsaacSin <Isaacgsds@gmail.com>
Co-committed-by: IsaacSin <Isaacgsds@gmail.com>