Use Canonicals for dependency gathering

[sliver007]

The IDependencyInfo interface is used in the dependency gathering process of the release operation to track dependency references. It is currently defined using String as the type for the references. This should be changed to use CanonicalType. All of the adapters should be re-visited to ensure that they, too, report dependencies as Canonicals rather than Strings.

[brynrhodes]

This is also relevant for the Value Set Manager project and all the use cases for value set libraries and manifests.