s3: read bucket owner and crtime from the entry-free bucket config

The owner index read the raw filer entry off BucketConfig, which no
longer carries one. Cache Crtime alongside IdentityId, and pass the
owner id rather than the entry through the ListBuckets visibility
checks so the scan and granted-bucket paths share one implementation.

weed/s3api/s3api_bucket_owner_index.go

@@ -166,12 +166,12 @@ func (s3a *S3ApiServer) resolveGrantedBuckets(r *http.Request, identity *Identit
 			}
 			continue
 		}
-		if !s3a.bucketVisibleToIdentity(r, config.Entry, identity) {
+		if !s3a.bucketVisibleToIdentity(r, name, config.IdentityId, identity) {
 			continue
 		}
 		granted = append(granted, ListAllMyBucketsEntry{
 			Name:         name,
-			CreationDate: time.Unix(config.Entry.Attributes.Crtime, 0).UTC(),
+			CreationDate: time.Unix(config.Crtime, 0).UTC(),
 		})
 	}
 	return granted