Integrate large payload support for SQS

[auvipy]

This adds support for handling large payloads in SQS. The 'sqs_extended_client' is imported and utilized for fetching file from S3 as payload when necessary.

As Kombu asynchronously fetches new messages from the queue, not using the standard boto3 APIs, we have to manually fetch the s3 file, rather than rely on the sqs_extended_client to perform that action

Relates to: celery/kombu#279