fix: Improved parsing and handling of backslashes

Fixes the issue where:

```
let arg = todo
echo -e "\n\n$arg"
```

Returns:

```

ntodo
```

Instead of:

```

todo
```

---

Fixes issue where:

```
echo -e "one\\\\\ntwo\\\\\nthree"
```

Returns:

```
one\\ntwo\\nthree
```

Instead of:

```
one\
two\
three
```