Feature Request: add support for policyfiles to chef_node resource of chef provider

[hashibot]

This issue was originally opened by @jugatsu as hashicorp/terraform#12893. It was migrated here as part of the provider split. The original body of the issue is below.

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It would be great if chef_node resource of chef provider also supports policyfiles arguments.
By comprasion, chef provisioner supports policy_name and policy_group arguments.

[rhoegg]

This would be nice for situations where we need to apply a policy to nodes only after chef provisioners have completed successfully. For example, we may want to use attributes of an instance to create a policy, then attach that policy to the nodes we created.