S3UTILS-207: Fix scuba metrics string concatenation bug

Parse objectsTotal and bytesTotal as integers before aggregation.
These values are read as strings from metadata, causing JavaScript's + operator
to concatenate instead of add.

Author: dvasilas

service-level-sidecar/report.js

@@ -73,8 +73,8 @@ async function getMetricsForBucket(sessionIds, timestamp, bucket, log) {
         return logResults
             .filter(result => result !== null)
             .reduce((acc, result) => ({
-                count: acc.count + result.value.metrics.objectsTotal,
-                bytes: acc.bytes + result.value.metrics.bytesTotal,
+                count: acc.count + parseInt(result.value.metrics.objectsTotal, 10),
+                bytes: acc.bytes + parseInt(result.value.metrics.bytesTotal, 10),
             }), { count: 0, bytes: 0 });
     }
     return warp10.getMetricsForBucket(timestamp, bucket.name, log);