[suggestion] Show encumbrance tooltip in unit designer

When we look at unit details for a unit on the worldmap, there's a neat encumbrance meter. When we hover over that, there's a neat tooltip that explains what it is, and why it matters.

I wish the same tooltip would show up when I design units in the unit designer. All we get is the number shown, ie 61 encumbrance. It is difficult to understand its importance when designing units without that particular tooltip.