Support state and individual resources

[jasonckeating]

Is your feature request related to a problem?

Yes, registry state is ignored by the Terraform provider. If a registry was configured in the UI, Terraform will overwrite it.

importing existing registries is not supported.

Describe the solution you'd like

Registries should be individual resources. So they can be managed individually and imported. Also, we are wanting to use a foreach so that we can programmatically add many registries.

example: We have many accounts that are members of an org. Would like Terraform to loop through each account and configure each registry, so many resources don't need to be manually configured.

Describe alternatives you've considered

for_each is not supported for specification blocks {}

Additional context

This has prevented us from hooking up all registries, since there are many. It has caused our work through the UI to be wiped out many times.