ByteBufferSlicePool allocated direct buffers should be reused

The pool can be recreated inside WildFly at every call to reload the server. With that, direct allocated buffers are just lost but, as pointed in the Javadoc of ByteBuffer:
"The contents of direct buffers may reside outside of the normal garbage-collected heap, and so their impact upon the memory footprint of an application might not be obvious. "

An out of memory error can be verified by reloading the WildFly server several times after performing a cli operation, that causes direct buffers to be allocated.