Use S3AsyncClient for better performance

[demaziej]

In addition to the S3Client use S3AsyncClient to improve download / upload performance by using parallel transfers.

• S3AsyncClient.builder().multipartEnabled(true)
• S3AsyncClient.crtBuilder()

See:

• https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/s3-async-client-multipart.html
• https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/crt-based-s3-client.html

The choice could be done in the extension <configuration>(for example client = Sync / Async / AsyncCRT) and also exposing some of the builder configuration:

• multipartEnabled
• thresholdInBytes
• minimumPartSizeInBytes
• targetThroughputInGbps