Add pinning feature for news and announcements

We should add a parameter for the newsItems widget to pin a news item.

The parameter could take a comma-separated list of news node IDs (e.g. 40804). This will then pin the news item to the top of the list of news items.

Currently, only OpenHW has been utilizing a pinning feature. We have been doing so by hardcoding the news item. The downside of this approach is that we cannot pin a news item from the newsroom API because we cannot handle the duplication of the pinned item and the same news item from the API.

Setting this as a low priority since it isn't really being requested by anyone.