Incorrect type on filters

[nazrhom]

Currently a query like

api.get({
    resource: 'release',
    options: {
        $top: 1,
        $orderby: 'id desc',
        $filter: {
            belongs_to__application: appId,
            commit: commitHash,
            push_timestamp: { $ne: null },
            status: 'success',
        }
    }
});

Is considered ill-typed by the client. The problem is with the sub-filter { $ne: null }. This happens because, with the current typings, a filter value can only be one of number | string | undefined.