Minor design improvements to the extended result screen

[stanriders]

I am aware of the possibly-one-day-definitely-upcoming redesign, but while it's not yet ready I've made a couple of small design improvements to the current result screen.

This includes:

• Slightly tighter and more consistent paddings
• StatisticPanel's header being consistent with other similar panels (it's using subsection design right now which probably made sense back when it was all one panel)
• More compact PerformanceBreakdown section
• Slightly less background blur and slightly more transparent statistics panels

Before:

After:

[peppy]

I dunno if this is worth it when it still looks like shit, but I'll give it 10 minutes.

[peppy]

I don't like this display format.

I don't think PP should be a 1/2 fraction thing.

I'd rather a second gray line saying "Maximum 102pp" beneath like it was before.

[peppy]

I don't mind making padding changes and stuff but let's not invent new display methods from nowhere.