Component: get rid of `onInitialStateRequest` in favour of call `setState` inside `onInit`

[dfilatov]

Currently:

class MyComponent extends Component {
    onInitialStateRequest() {
        return { a : 1 };
    }

    onInit() {
        ...
    }
}

Proposed:

class MyComponent extends Component {
    onInit() {
        this.setState({ a : 1 });
        ...
    }
}