ran into this error while running terraform on a container and saving state to Consul. I suspect my policy needs tweaking but it's impossible to tell with an error like this:

```
╷
│ Error: Failed to save state
│ 
│ Error saving state: consul CAS failed with transaction errors:
│ [0xc0006e93c8]
╵
```

This PR makes the will include the error messaage in the details so I can continue debugging

this is what i get for submitting PRs late at night

Co-authored-by: Chris Thain <32781396+cthain@users.noreply.github.com>

Co-authored-by: Chris Thain <32781396+cthain@users.noreply.github.com>