Preserve Expiry on unsupported cluster returns unexpected Exception

In the test preserveExpiryThrowsFeatureNotAvailable in the file QueryErrorTest.

In this test we try to set preserve expiry on a cluster that does not support it (6.6 for example). We expect a Feature not available exception which I think makes the most sense, but will also accept a generic SDK_COUCHBASE_EXCEPTION, likely for Go. I do not see in the RFC a specified error that must be returned so if that is the case and the plan is for CXX to continue returning this error type then I can modify the test to accept this. If that is the case I can move this issue to the SDKQE board and make the change.