Incorrect currency in gift card notification

[RomanovM]

nopCommerce version: 4.50

1. nopCommerce version:
   4.5

2. Expected behavior:
   Purchasing a $10 USD giftcard should show a USD symbol in the gift card email. As this is the value of the giftcard, in the stores primary currency

3. Actual behavior
   Purchasing a $10 USD giftcard shows the currency symbol of whatever was used to purchase it (for example, £10)

4. Steps to reproduce the problem
   Change the store's currency to something other than what the giftcard is being sold in, proceed through checkout, then view the giftcard sent out via email

5. Any private modifications you made to your nopCommerce
   Nothing that would affect this behavior

Source: https://www.nopcommerce.com/boards/topic/95523/gift-card-emails-show-incorrect-currency-symbols

Note: to reproduce the problem enable ordersettings.activategiftcardsaftercompletingorder setting and activate a payment method with the immediate capture feature

See also: #6258

[skoshelev]

Closed #6429