Copy and CopyPart changes for compression (#6669)
Copy and CopyPart changes for compression (#6669)

This PR fixes

- The target object should be compressed even if the
  source object is not compressed.

- The actual size for an encrypted object should be the
  `decryptedSize`
balamurugana/minio,harshavardhana/minio,aead/minio,aead/minio,donatello/minio,krishnasrinivas/minio,krishnasrinivas/minio,krisis/minio,fwessels/minio,harshavardhana/minio,aead/minio,donatello/minio,fwessels/minio,krishnasrinivas/minio,krishnasrinivas/minio,fwessels/minio,harshavardhana/minio,balamurugana/minio,NitishT/minio,NitishT/minio,vadmeste/minio,jimjag/minio,fwessels/minio,harshavardhana/minio,jimjag/minio,minio/minio,jimjag/minio,aead/minio,harshavardhana/minio,aead/minio,aead/minio,minio/minio,NitishT/minio,harshavardhana/minio,harshavardhana/minio,harshavardhana/minio,jimjag/minio,aead/minio,vadmeste/minio,aead/minio,NitishT/minio,krisis/minio