SegmentBlob equals check should verify compaction in both directions

It looks like the SegmentNodeState checks compaction in one direction [0], while the SegmentBlob checks in the other direction. This will not break anything as the fallback is to use byte comparison, but it will be terribly slow.
I'm proposing to verify both directions in the #equals check, to make sure we don't miss out.

[0] https://github.com/apache/jackrabbit-oak/blob/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/SegmentNodeState.java#L401
[1] https://github.com/apache/jackrabbit-oak/blob/trunk/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/SegmentBlob.java#L198