Dynamically fetch servers whilst scrolling

[reesvarney]

When running a very loose set of filters e.g. show empty servers, the server data often ends up being multiple MBs, to fix this there should be a limit of e.g. 100 servers that are fetched at once, before retrieving the next set whilst scrolling. However, this will need to be done in a way which allows it to stay up to date as you could get multiple copies of the same server if it is sorted by connected drivers and the drivers leave between the first and second fetch