[Bug] - REST `Unsupported Authorization Type` error missing `ArgumentName` and `ArgumentValue`

[lrm25]

Describe the bug
An example of the error returned by direct:

   <?xml version="1.0" encoding="UTF-8"?>
   <Error><Code>InvalidArgument</Code><Message>Unsupported Authorization Type</Message><ArgumentName>Authorization</ArgumentName><ArgumentValue>AWS-HMAC-SHA25 Credential=AKIAQ****/20251217/us-east-1/s3/aws4_request,SignedHeaders=host;x-amz-content-sha256;x-amz-date,Signature=278268c42687660cb16e9f1aa4237d336a569c9ca0e3a636b69c683952ef1abb</ArgumentValue><RequestId>B7MENPA8C0N9BXV6</RequestId><HostId>cb8z/pwZu5/K1STFhuprySEe0Gsel6bP0A3gaEtQ95rrGHYphVdIyEnSQjCK2IoSsB8DM4OP7fU=</HostId></Error>

versitygw:

   <?xml version="1.0" encoding="UTF-8"?>
   <Error><Code>InvalidArgument</Code><Message>Unsupported Authorization Type</Message><Resource></Resource><RequestId></RequestId><HostId></HostId></Error>

The ArgumentName and ArgumentValue elements are missing.

To Reproduce

1. Start versitygw, e.g.: ./versitygw --access=AKIA**** --secret=******** --region=us-east-1 --iam-dir=/Users/lukemccrone/devel/versitygw/iam --cert /Users/lukemccrone/devel/versitygw/cert.pem --key /Users/lukemccrone/devel/versitygw/versitygw.pem posix --versioning-dir /tmp/versioning /tmp/gw
2. Send an invalid authorization scheme. With generateCommand.go, this can be done with -authorizationScheme AWS-HMAC-SHA25.

Expected behavior
Error returns ArgumentName and ArgumentValue.

Server Version
Version : v1.0.19
Build : dd8a22d
BuildTime: 2025-12-17_06:42:53PM
Darwin Lukes-MacBook-Pro.local 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:28:30 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6030 arm64