Add support to newline after decorator

[amazzoccone]

Actually there is no way to force an empty line between decorator types. Example:

@Prop() user: IUser;
@State() client: IClient;
protected componentWillLoad(): void {
  ..
}

It should be cool to be:

@Prop() user: IUser;

@State() client: IClient;

protected componentWillLoad(): void {
  ..
}

Maybe a rule like new-line-after-component-member=true or new-line-after-decorated-member=true. We could separate method new lines in other rule: newline-after-method.

Thanks!