[CSS] Fix menu section items height
There is a subtle visual issue with light & dark skins :
- Select "Reports"
- Click on "Budget"
You might notice that the "Budget" will be move a bit toward the top. This is due to the fact the "Reports" had a height of 50px (48 + border due to the active class) and now only has a height of 48px (no border since the active class is on "Budget").
This MR fixes it by making the items have all the same height, no matter if they're active or not.