For a non-existent user server would return STS not initialized
```
aws --profile harsha --endpoint-url http://localhost:9000 \
sts assume-role \
--role-arn arn:xxx:xxx:xxx:xxxx \
--role-session-name anything
```
instead return an appropriate error as expected by STS API
Additionally also format the `trace` output for STS APIs
While Tracing requests on server, type assertion on logger.ResponseWriter
caused nil pointer exception because of recordAPIStats{} being
used as ResponseWriter. This PR avoids the type assertion and
initializes a new logger.ResponseWriter.
Fixes regression introduced in #8003
It is observed that when `mc admin trace` is being
used due to ResponseWriter wrapper, we loose information
about statusCode,statusText for audit logging.
This PR fixes this behavior
When an S3 client issues a GET request with range specified, Minio
server returns some partial data with 206 http code. The latter
is sent in MINIO_HTTP_TRACE output which is incorrect. This PR
fixes the issue.
When MINIO_TRACE_DIR is provided, create a new log file and store all
HTTP requests + responses data, body are excluded to reduce memory
consumption. MINIO_HTTP_TRACE=1 enables logging. Use non mem
consuming http req/resp recorders, the maximum is about 32k per request.
This logs to STDOUT, body logging is disabled for PutObject PutObjectPart
GetObject.
Harshavardhana