post https://{base_url}/core/api/v1/locations/country/upload
This endpoint is used for uploading country info in bulk using a file. The API can be used to upload a file (up to 2MB) with country information. Callback can also be provided along with file to notify the status of file processing. In callback, fileId, requestId, status, unProcessedCount, processedCount, and failureReason are provided.