changed from findDhtValue() to getHash, changed it's params too

also changed the params the fn expects to a targetNode which is the
bdId target node id that the request will be made to, and a bdNodeId
which is the key to fetch from the targetNodes hash.
updated bdNodeManager to use getHash, and to call send_get_hash_query() directly

the idea being that we’ve already located the node to make the request
to by making a find_node request(s) first.
findDhtValue change to getHash in interface base class BitDhtInterface
storage updated to use get hash
paper notes
trim that whitepace