Add cold level medipacks

[lahm86]

Adds some medi compensation for cold levels. The calculation is a bit arbitrary but it results in a fair allocation imo.
Resolves #511.

[rr-]

Why the sanity check? If I read things right, this will never be true given the current logic.

[lahm86]

It's for Lud's Gate mainly. We don't define extra UPV locations for it as they're already in the level, so ImportUPV doesn't do anything, yet we still want to add medis when it's cold here. I initially had the medi code at the end of ImportUPV but then realised this still left Lud's without, as it exits early.

[chreden]

How come you only get medis if you have a UPV?

[rr-]

TR-Rando/TRRandomizerCore/Processors/TR3/TR3SequenceProcessor.cs

Lines 92 to 98 in 4573c37

	if (!level.Is(TR3LevelNames.ANTARC) && !level.Is(TR3LevelNames.RXTECH))
	{
	// The UPV keeps Lara warm underwater so make this available for
	// those levels that have long underwater sections.
	ImportUPV(level);
	AddColdLevelMedis(level);
	}

This is for levels that have freezing water but aren't antarctica or rx tech mines. These levels get both UPV and extra meds. At least that's how I read it; I'm not sure but it sounds like it should be the other way around.

[lahm86]

We don't add UPVs in all cases - Caves of Kaliya, Puna etc. So we don't want to add medis in these cases as they're intended mainly for getting off the UPV to pull a lever for instance. We could by all means, but it'd be free medis for no reason.

We don't do anything special in Antarctica or RX-Tech as they're cold OG, so we don't need to fiddle with the design really.

I suppose we could do a water room check instead of whether or not it's been decided previously to add a UPV, but this way it leaves it more loose - if we decide to add to other levels, it's just a case of defining vehicle locations here.