Enhance SDK error message to show the right error message so that the user can easily debug and solve issues.

In reference to the forum post 

The user was getting "client internal error" which is hard to debug as to why the error occurred. 

In this case the user was using a N1QL query to JOIN on two buckets out of which user did not have enough access set up on one of the buckets.

It would have been easy if the error message was something like 'unauthorized access on bucket <bucket-name>' something along those lines.