Memory leak in CachedStore when using ByteBufferSerde as key serde

ByteBufferSerde uses relative bulk get to serialize the provided ByteBuffer which changes its internal position. ByteBuffer's `equals` and `hashCode` depend upon its remaining elements, i.e. on its position. This means that when using ByteBuffers as keys in the CachedStore, flushing cache contents to the underlying store changes their hashCode. Since the hashCode for the key no longer matches the one used when inserting it into the map, the LinkedHashMap cannot correctly evict or remove these entries, leading to a memory leak.

Changing ByteBufferSerde to use absolute get operations or duplicate the provided ByteBuffer before copying should fix this issue.