MINIFICPP-2792 Fix S3 upload above 2GB on Windows

[lordgamez]

• Set content length to avoid narrowing size to int on Windows
• Add MinifiToAwsInputStream to wrap MiNiFi InputStream and avoid stream copy

https://issues.apache.org/jira/browse/MINIFICPP-2792

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[Copilot]

Pull request overview

This PR updates the AWS S3 upload path to avoid copying FlowFile content into an intermediate Aws::StringStream, and to explicitly set request content length so large uploads work correctly on Windows. In the MiNiFi AWS extension, that means PutS3Object now streams directly from MiNiFi io::InputStream into the AWS SDK request bodies.

Changes:

• Replace the old copy-based readFlowFileStream helper with a new MinifiToAwsInputStream adapter around io::InputStream.
• Explicitly set ContentLength on both single-part and multipart S3 upload requests.
• Update S3 test mocks/helpers to model body consumption more like the AWS SDK for multipart uploads.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
extensions/aws/tests/MockS3RequestSender.h	Adjusts test mock behavior so multipart request bodies are consumed/read more like the real SDK.
extensions/aws/s3/S3Wrapper.h	Removes the old helper declaration for copying FlowFile data into an AWS string stream.
extensions/aws/s3/S3Wrapper.cpp	Switches S3 uploads to the new stream adapter and sets request content lengths explicitly.
extensions/aws/s3/MinifiToAwsInputStream.h	Adds a new streambuf/iostream adapter that exposes MiNiFi io::InputStream as an AWS-compatible input stream.

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