In order to include condition block results in the JSON plan output, we
must store them in the plan and its serialization.
Terraform can evaluate condition blocks multiple times, so we must be
able to update the result. Accordingly, the plan.Conditions object is a
map with keys representing the condition block's address. Condition
blocks are not referenceable in any other context, so this address form
cannot be used anywhere in the configuration.
The commit includes a new test case for the JSON output of a
refresh-only plan, which is currently the only way for a failing
condition result to be rendered through this path.
This is part of a general effort to move all of Terraform's non-library
package surface under internal in order to reinforce that these are for
internal use within Terraform only.
If you were previously importing packages under this prefix into an
external codebase, you could pin to an earlier release tag as an interim
solution until you've make a plan to achieve the same functionality some
other way.
