New: specify list of jobIds in Jobs component.

This allows us to create a shortlist of jobs in the DFP component:

```
<script class="breakout__script">
(function(){
    if(typeof require === 'function') {
        require(['common/modules/commercial/loader'], function(CommercialComponent) {
            var slot = document.querySelector('[data-name="merchandising"]');
            var c = new CommercialComponent({
                config: guardian.config,
                oastoken: '%%CLICK_URL_ESC%%',
                jobIds: 1234,5678
            }).init('jobs', slot);
        });
    }
})();
</script>
```