Support for booleans

`deno_bindgen` doesn't allow bool for some reason..
we need to use `u8` as return-type or parameters and then cast them, which is pretty annoying..
adding `bool` to `deno_bindgen`'s native-type would be much better...

```rs
#[deno_bindgen]
pub fn is_fun()-> bool {
true
}
```

Start at deno_bindgen's native-type handling and trace how the example `pub fn is_fun() -> bool` is processed. Compare the existing supported parameter and return types, then run the relevant existing tests or examples. Done means bool is accepted for native parameters and return values without u8 casts, with coverage for the shown function.

Written by the indexing model from the issue text.