Cannot remove transaction block on user if refund fails

[habbes]

When a user initiates a refund, their account is blocked from making further transactions. This block is removed when the refund completes successfully. However, if the refund fails, the block is not removed. This means that they cannot retry the refund, nor can they make other transactions.

We should fix this such that the block gets removed when the transaction completes (whether it fails or succeeds).

After analyzing the issue, I concluded that a fix would require the following changes:

• The transactionCompleted event, which is currently emitted only when the transaction is marked as successfully, should also be emitted also when the transaction is marked as failed (success and failed are both final states of the transaction). This happens in the handleProviderNotification() method of the transaction service.
• The call toremoveTransactionBlockFomRefund() in Users.handleRefundCompleted() should be made whether the the refund has succeeded or failed. However, the refund count should not be incremented if the transaction has failed.