Adjust limb encumbrance calculations

[Venera3]

Summary

Bugfixes "Tweak limb encumbrance calculations"

Purpose of change

Some limb scores' effect was communicated poorly to the player, especially torso encumbrance which stopped having an effect on melee rolls but still displayed the melee roll modifier in its @ menu entry.
Fixes #52109, #50915 and #52418

Describe the solution

• Added footing_score, moved balance_score's effect on movement costs over to it (normal feet have 0.5 each)
• Adjusted the movement cost modifier calculations to take movement_speed_score and footing_score in a 2:1 proportion into account (was 1:1)
• Added balance_score to the torso and arms (0.7 / 0.15 /0.15 respectively) to restore torso encumbrance's effect on melee
• Adjusted melee stamina cost calculations to take arm encumbrance (lifting_score) into account instead of only limb HP
• Added encumbrance_threshold, a limb field to define at which level of encumbrance do the limb's scores start to decrease and added it to feet, legs, arms, torso and head - with the goal of "casual" wear not having any encumbering effect
• Added encumbrance_limit, defining the level of encumbrance where the limb stops contributing its scores completely - this is necessary because the normal encumbrance scaling never really reaches 0. Default 100, eyes have 60 turning welding goggles into improptu blindfolds without using the blind flag
• Adjusted the encumbrance displays and messages to be (hopefully) a bit more useful

Describe alternatives you've considered

Break it up a bit more, but they're related.
Audit the encumbrance values of all pieces of gear - there is a lot of weirdness, and I have mutant bits to enlimben. I tried to eyeball a level of encumbrance_thresholds where your everyday wear wouldn't have an effect, but there's probably an outlier or three somewhere.
Use encumbrance_threshold as a "grace" area, and apply the full scaling apart from it, but that felt a bit too jumpy for my tastes - delaying scaling feels smoother.

Testing

The @ menu values change as expected.
encumbrance_threshold limits (or raises, for negative values) the effect of gear.
encumbrance_limit triggers, has the expected effect.
Torso encumbrance makes you miss, arm encumbrance makes swings more tiring, walk speed is mostly determined by leg encumbrance, with feet playing a smaller role.

Additional context

@KorGgenT

The threshold values for encumbrance are 5 for feet (meaning boots have a minimal effect), arms, legs and torso and 10 for head. I'm open to suggestions on that front, but they feel like the right ballpark.

[dseguin]

Looks like we had similar ideas: #53069
I'll wait until this gets merged to migrate the new score.

[Terrorforge]

I tried to eyeball a level of encumbrance_thresholds where your everyday wear wouldn't have an effect, but there's probably an outlier or three somewhere.

The obvious thing to mention here is that these values leave the heavy survivor suit almost completely unaffected by encumbrance - but I don't expect the fact that the heavy survivor suit is completely busted comes as a shock to anyone.

[Venera3]

Yeah, armor encumbrance is all over the place - or rather, armor is universally low-encumbrance, with clothing being annoyingly heavy - jeans have a fitted encumbrance of 5-9 depending on their fullness (and four 1L pockets, while we're at it), with fitted plate armor clocking in at 14. I briefly considered tweaking a bit here and there, but this type of stuff needs a thorough audit by one person who has a clear idea of what they want to reach instead of n+1 people "while I'm here"ing it.

[Terrorforge]

Basically every aspect of armor needs a comprehensive audit. Coverage is weird too, layering probably needs a seeing-to, pockets don't make sense, i.e. one of the many weird aspects of survivor suits is that you can somehow stuff 8L of crap into a garment that ostensibly fits underneath a suit of gothic plate. I have a lot of thoughts on that stuff, bur unfortunately I don't have the bandwidth to be the One Person who knuckles down and actually does it.

But I was under the impression that someone was leading the charge to euthanize at least the heavy survivor suit and replace it with something modular. Maybe that was more of an "Eventually(tm)" thing?

[Inglonias]

The fact that torso encumbrance didn't affect melee rolls was nice, though I understand that it's a bug that should be fixed. I will still be sad to see it go.

[Venera3]

Bumped down the thresholds a bit. "I'm too encumbered by normal clothes, this is bullshit" is a better incentive to start working on something than "neat, I can wear this with no downsides", after all.