Additional filters for `GET#Refunds` endpoint

Changes implemented:

Add `updated_at` field for Refunds object

Add updated_at field for Refunds object displayed in CoinGate V2 API endpoints


GET Outgoing Fees API endpoint

Added new API endpoint to List Outgoing Fees:


Order Blockchain Transactions API

Added new API endpoints to get Order Blockchain Transactions:


JSON Payment Callback Format

Now allows to change Payment Callback format to JSON. If you want to set for currently used API APP, login to your account dashboard, go to Merchant -> API -> Apps and click Edit.


Ledger Transactions API Endpoints

Added new API endpoints to get ledger transactions:


Fees in Payment Callback

Added fees parameter in Payment Callback