scan_folded_as_literal not behaving plausible with trailing whitespace

Config:
```
formatter:
type: basic
scan_folded_as_literal: true
```

Minimal reproducible example:

```yaml
foo: >
lorem ipsum
```

(note there is a trailing whitespace after "lorem ipsum ")

is being formatted to

```yaml
foo: "lorem ipsum \n"
```

It took me quite a while to figure out that this is the underlying reason why our 20+ line folded strings got turned into single lines. So I guess that this behaviour is for the very least misleading and probably also not desired.