1. Return resource inputs as well as resource state from Read()
2. Return a list of properties that changed from Diff()

We implement the former by reading the last applied configuration
from the `kubectl.kubernetes.io/last-applied-configuration`
annotation in the live object state. If this key is not present, no
inputs are populated and the old inputs are retained. These changes
also update the provider to set this field during `Create` and
`Update`.

We implement the latter by scanning the JSON diff and recording the
names of the top-level properties that changed. The engine uses this
information to filter diffs to only those that are semantically
meaningful.

These changes required a couple of bugfixes:
- Old names are only adopted if the old resource was auto-named. This
  ensures that a name must be specified when importing a resource that
  was not autonamed.
- URN to GVK conversion was fixed for resources in the "core" group.
  These resources have no group part in the GVK. Parsing was also
  simplified through the use of pulumi/pulumi's token manipulation
  functions.
- When reading a resource, the GVK for the resource to read is now
  pulled from the URN if it is absent from the inputs.