Grid view per branch

The grid view sometimes shows no builds when filtering by branch. Vlad did some investigation and found out that this is caused by a weird design decision in the buildbot code where the last changes and the last builds are fetched from the database independently and then filtered. This means, that if it happens to have builds from the selected branch, then they are shown otherwise not.

There are current challenges with JavaScript and Angular. Vlad uses the developer interface in Google Chrome. Still pursuing the default scenario of fixing the issue. But there is another option on how to fetch data to the grid view. That is out-of-focus for the Buildbot API, though. Hence Vlad still focuses on the current solution, so that we can submit a PR to Buildbot, with a patch that can be maintained by the Buildbot team.