Fixes#11212
The import graph builder was missing the transform to setup links to
parent providers, so provider inheritance didn't work properly. This
adds that.
This also removes the `PruneProviderTransform` since that has no value
in this graph since we'll never add an unused provider.
Ensure that each instance of BasucGraphBuilder gets a name corresponding
to the Builder which created it. This allows us to differentiate the
graphs in the logs.
This uses the new NodeApplyableProvider graph nodes. This will just make
it easier for us in the future to adopt new graph transforms by starting
to use the new ones here.
