TransportClient: Improve logging, fix minor issue

In order to return more information to the client, in case a TransportClient
can not connect to the cluster, this commit adds logging and also returns the
configured nodes in the NoNodeAvailableException

Also a minor bug has been fixed, which propagated exceptions wrong, so that an
invalid request was actually tried on every node, if a regular connection failure
on the first node had happened.

Closes #6376