CursorResponseBuilder::done() and CursorResponseBuilder::appendCursorResponseObject() build responses with a NamespaceString field that calls `NamespaceStringUtil::serialze()`, which will depend on a `SerializationContext` object to specify serialization behavior.  We need to pass the `SerializationContext` object down the layers in order to have `done()`  and `appendCursorResponseObject()` serialize correctly.

As the goal of these changes are in pursuit of fixing tests that will fail once serializeForCommands and deserializeForCommands are plumbed in, no new tests are being added for this ticket.