feature/s3/transfermanager: allow control over default upload checksums #3556

Describe the feature

S3 Transfer Manager currently sends upload checksums as trailers using Content-Encoding: aws-chunked.

Could it support calculating the checksum before upload and sending it in the corresponding request header instead?

This would give callers more flexibility, as some S3-compatible storage services have limited support for aws-chunked.

Use Case

 transfermanager.New(client, func(o *Options) {
      o.ChecksumLocation = ChecksumLocationHeader // Header or Trailer (Default Trailer)
  })

Proposed Solution

No response

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

AWS Go SDK V2 Module Versions Used

github.com/aws/aws-sdk-go-v2/feature/s3/transfermanager v0.1.11

Go version used

go 1.26.6