[FIXED JENKINS-31487] (#2542)

There were two issues preventing the build history from updating properly:
1) The next build number being fetched wasn't taking into account running builds, so any builds already running when the page is refreshed would be ignored. The fix was to use nextBuildNumberToFetch if it is available (which is the case if there are running builds) and to fall back to the next build otherwise.
2) The first transient build key (used to clear out builds from the history that are being updated) wasn't being set when the page first loads. This was fixed by making getHistoryPageFilter calculate the value so that it happens in all cases rather than just during the ajax call.