[ENHANCE] Send connector in refund response

[Abhicodes-crypto]

Feature Description

Add field connector in api_models::refunds::RefundResponse.

Possible Implementation

We store connector field in storage_models::Refund. Map it to the field in RefundResponse

Have you spent some time to check if this feature request has been raised before?

• I checked and didn't find similar issue

Have you read the Contributing Guidelines?

• I have read the Contributing Guidelines

Are you willing to submit a PR?

Yes I am willing to submit a PR!