`TestCheckOutput` and `TestMatchOutput` do not support collection types

### terraform-plugin-testing version

```
github.com/hashicorp/terraform-plugin-testing v1.4.0
```

### Expected Behavior

The output name should support the count and indexing syntax supported by the attribute check functions

### Actual Behavior

When using the count and indexing syntax on a `map` output, the following error is returned:

```
* Check 6/7 error: Not found: stack_outputs.%
* Check 7/7 error: Not found: stack_outputs.DataOut
```

When passing the top-level output name, the following error is returned:

```
* Check 6/6 error: Output 'stack_outputs': expected "try_this", got &terraform.OutputState{Sensitive:false, Type:"map", Value:map[string]interface {}{"DataOut":"pre-in1-post"}, mu:sync.Mutex{state:0, sema:0x0}}
```