Allow `azd env refresh` against an environment that doesn't exist locally

I cloned a project that doesn't have an .azure folder yet.

I want to pull the environment info down.

I run `azd env refresh -e envname` expecting it to prompt for me to select a sub to pull the env from.

But instead I get this:

```
Error: no project exists; to create a new project, run `azd init`.
```

I'd expect it to let me select a sub and continue with the refresh.