Promise async code style

_input from @erossignon_

We have different code styles used throughout the code for promises.

```JS
method(...): Promise<...> {
return new Promise<...>((resolve, reject) => {
// actual code
}
}
```

or

```JS
async method(...): Promise<...> {
// actual code
}
```

Shall we leave it as is or go with one or the other?
The 2nd variant seems cleaner and less verbose. I don't believe there is any downside...