fix: Hats in twoslash errors should be commented

[Gerrit0]

Also fixes the bug where errors which took up the whole line would result in an empty line being included.

```ts twoslash
foo
```

followed by

```ts twoslash
declare const x: { a?: { b: boolean, c: string }}

if (x.a!.b)
    x.a.c + foo
```

now produces:

[robertt]

Perfect, can some empty lines be put between the if statement for readability?