Some exception classes do not handle first positional arg being a string message

The CouchbaseException class accepts all optional positional arguments, but the first arg, if it exists, is expected to be a pycbc_core exception type (this is an artifact of when the bindings were first re-written and should potentially be re-worked in the future). However, there are instances when the SDK raises exceptions when only providing a message as the first positional arg. This causes issues when a user tries to access the str/repr of the exception.

The SDK should either set the message kwarg or update the _init_ of all exceptions to handle this use-case. This is correctly handled for most of the commonly raised exceptions, but should be applied in all instances.