Add error types for state/planfile version incompatibility

[kmoe]

There is a class of CLI errors of the form:

            Error: Invalid plan file
            
            Failed to read plan from plan file: plan file was created by Terraform
            0.12.29, but this is 0.13.0; plan files cannot be transferred between
            different Terraform versions.

Handle all these cases with well-known error types:

• Plan file created by different version
• State file created by later version
• State file created by 0.12 without explicit backend configuration and with a name other than "terraform.tfstate", and accessed in 0.13 "Unknown provider" when upgrading to 0.13 with a non-default state file name terraform#25920

The only "format_version" presently known by terraform-json and this library is 0.1. Add at least an e2e test that will flag if another version is encountered. There's no need to error at runtime unless and until the Terraform CLI does so.