When aggregation has a view, it will attempt to resolve that view onto the base collection, and create a new agg command request based on the resolved namespace.  However, this loses the serialization flags on the existing request that can cause serialization issues, so we need to copy the serialization context object over to the new request at the point of creation.

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.