feat(balance): set arm guard/greave items to use same layer as comparable torso armor items

[chaosvolt]

Checklist

Required

• I wrote the PR title in conventional commit format.
• I ran the code formatter.
• I linked any relevant issues using github keyword syntax so it can be closed automatically.
• I have committed my changes to new branch that isn't main so it won't cause conflict when updating main branch later.

Optional

Purpose of change

This applies some consistency updates to armguard and legguard/greave items, with the goal of making the layer they're on more consistent with their torso and suit counterparts. The majority of such items tend to be on the outer layer, so it'd be reasonable to have most of the arm and leg items match on layer used. Plate and paper items were notably consistent with this already, being outer layer (as plate cuirass) and strapped layer (as bookplate) respectively.

Describe the solution

1. Set bronze greaves and leg guards to OUTER layer, matching that of bell cuirass. Also affects metal/item arm guards/greaves, since bronze arm guards inherit from metal arm guards. Bone greaves likewise affected due to inheriting from bronze greaves.
2. Switched hard neoprene arm/leg guards to OUTER layer, since the chest guard is on that layer.
3. Scrap arm/leg guards set to OUTER layer, as scrap cuirass is.
4. Leather vambraces set to normal layer, as leather arm guards and leather body armor is. Would normally say it might be okay on outer layer but with most mundane shirts no longer automatically clashing with other items it won't cause as many edge cases of weird-looking encumbrance penalties as it used to.
5. Bone vambraces set to OUTER layer, via extends since they copy from leather vambraces. Consistent with bone curiass and with the update to bone greaves.

Describe alternatives you've considered

1. Setting football armor, bookplate, and 2x4 armor to outer layer. Seems reasonable to leave the absolutely bulkiest wannabe armor still on the strapped layer since they're all at least consistent with other pieces in the same set.
2. Messing with the layers of leather and chitin armor. Seems okay to have them on normal layer to have them be something you could wear under other armor items (bone armor over leather or scaleskin armor for example, same idea as with mail letting you wear plate over it).

Testing

Checked affected files for syntax and lint errors.

Additional context

[RoyalFox2140]

Consistent inconsistency in the entire armor base. Love it