 add helpers for repeated code in bucket and object info  (#3251)
 add helpers for repeated code in bucket and object info  (#3251)

Use bucketInfo2ClientContent() and objectInfo2ClientContent()
extensively to avoid code duplication.
vadmeste/mc,krisis/mc,vadmeste/mc,minio/mc,krisis/mc,balamurugana/mc,minio/mc,balamurugana/mc