After using the new CPS APIs to update a project, you may at times need to
know when (and perhaps expedite) the IVsHierarchy, DTE, and other legacy
shims have been updated with the latest project state.
To accomplish this, you must acquire the
IProjectTreeService export and call its PublishLatestTreeAsync method.
That method returns a Task that completes when the IVsHierarchy object
model has been updated.