s3a audit logs to publish range start/end of GET requests in audit header

we don't get the range of ranged get requests in s3 server logs, because the AWS s3 log doesn't record that information. we can see it's a partial get from the 206 response, but the length of data retrieved is lost.

LoggingAuditor.beforeExecution() would need to recognise a ranged GET and determine the extra key-val pairs for range start and end (rs & re?)

we might need to modify HttpReferrerAuditHeader.buildHttpReferrer() to take a map of <string, string> so it can dynamically create a header for each request; currently that is not in there.