Uploading files to S3 using POST is not supported by AWS

[okovalenko0]

Describe the bug

When accessing Minio API "CreateMultipartUpload" with the HTTP post method, you get "Uploading files to S3 using POST is not supported by AWS, use PUT instead."

To Reproduce

Steps to reproduce the behavior:

1. Create HttpRequestMessage with HttpMethod.Post, and URL - http://localhost:9000/documents/02ccb210-bba2-42e2-b8d7-49891759978f?uploads=
2. Use Signer.SignAsync(request, null, request.Headers, DateTime.UtcNow, region, "s3", credentials); to sign the request.
3. See error

Expected behavior

No error, request successfully signed and sent

Desktop:

• OS: Windows
• Version 22631.4602

Additional context

Package version is 5.0.0

[github-actions]

Hi there and welcome to this repository!

A maintainer will be with you shortly, but first and foremost I would like to thank you for taking the time to report this issue. Quality is of the highest priority for us, and we would never release anything with known defects. We aim to do our best but unfortunately you are here because you encountered something we didn't expect. Lets see if we can figure out what went wrong and provide a remedy for it.

[okovalenko0]

Official docs on Amazon say, that to initialize multipart upload you should use POST.
Also, in their examples they use ?uploads query parameter without value and =, what also cause an exception.