This is a generic error type that can be used by multiple protocols to describe errors that can
occur while processing a request. The error type supports adding an additional error code in cases
where there is an underlying system error.
The type will be used to describe errors that occur while processing requests by BHttpSession, and
it is generally going to be thrown by the receiving BHttpResult.
Change-Id: I76c0bbaedd38df8cfb79159c4beae2fbf1350aab
