I left this out originally because it's not needed for the status "dashboard"
view (except on really tiny screens); however, it *is* useful after pressing `a`
to show the all branches log, and even more so for people who use the
"statusPanelView: allBranchesLog" config. And it doesn't really hurt for the
dashboard view either, so just enable it always rather than making a distinction
which view we are showing.
This is very similar to the same menu in the Files panel, except that it works
on whatever diff is currently shown in the main view, including range diffs
either in diffing mode (shift-W), or from a range selection of commits.