MQL fails to print failing `containsOnly` entries inside of blocks

Without the block:

```
> [1,2,3].containsOnly([1,2])
[failed] [].containsOnly()
  expected: == []
  actual:   [
    0: 3
  ]
```

Within a block:

```
> mondoo { [1,2,3].containsOnly([1,2]) }
mondoo: {
  [].containsOnly(): false
}
```

Analysis shows the AST is basically identical, i.e. this is not a code expansion issue but a printing issue.

as reported by @scottford-io 