For inexplicable reasons, the top row of pixels on our tabs, new tab
button, and caption buttons is totally unclickable. The mouse simply
refuses to interact with them. So when we're maximized, on certain
monitor configurations, this results in the top row of pixels not
reacting to clicks at all.
To obey Fitt's Law, we're gonna hackily shift the entire island up one
pixel. That will result in the top row of pixels in the window actually
being the _second_ row of pixels for those buttons, which will make them
clickable. It's perhaps not the right fix, but it works.
After discussion, we think this is a fine fix for this. We don't think
anyone's going to miss the top row of pixels on the TabView. The original
bug is painful enough for the subset of users it impacts that this is an
acceptable trade. Should a better fix be found, we can absolutely do that
instead.
Closes#7422