check: Implement terraform providers schema -json ingest

[bflad]

The terraform providers schema -json command can be used to output details about the current schema of a Terraform Provider (from Terraform Core's perspective). This information will allow for (optional) future checks to verify that every resource/data source and each of their schema attributes are documented, for example.

Recommended flag: -provider-schema-json=FILE

We may be able to instead read the schema directly in the future if the Terraform Provider binaries are enhanced to output this information without starting the RPC server.