These changes add support for passing `ignoreChanges` paths to resource
providers. This is intended to accommodate providers that perform diffs
between resource inputs and resource state (e.g. all Terraform-based
providers, the k8s provider when using API server dry-runs). These paths
are specified using the same syntax as the paths used in detailed diffs.
In addition to passing these paths to providers, the existing support
for `ignoreChanges` in inputs has been extended to accept paths rather
than top-level keys. It is an error to specify a path that is missing
one or more component in the old or new inputs.
Fixes#2936, #2663.