Fix exitcode bug introduced in PR/125

[dmsolutionsmn]

Due to #125 any terraform exit code of 2 will be considered passing even when it is a valid failure.

For example, terraform fmt can return 0, 2, or 3. (see https://github.com/hashicorp/terraform/blob/v1.9.3/internal/command/fmt.go#L96 )

• 0 - success
• 2 - has errors
• 3 - check is enabled and failed to pass check

The proposed solution in this PR is to verify that -detailed-exitcode argument was passed in. Additional test scenarios were added to cover the original pull request and this change.

[hashicorp-cla-app]

All committers have signed the CLA.