Added "overlay" functionality for player/NPCs.

New tileset IDs:
- overlay_worn_{ITEM ID}, overlay drawn over the character when the item is worn
- overlay_wielded_{ITEM ID}, overlay drawn over the character when the item is wielded
Removed superfluous null-check for worn items.
Fix draw_entity_with_overlays return type.

Function doesn't return anything.
Template update
Merge pull request #9012 from VlasovVitaly/pot-update

Translations template update
Replaced item.type->id with item.typeId() in player::get_overlay_ids()
Craftable hand-cranked autoshotgun.

A survivor-craft item, the only way to get one is to make it yourself or
luck out on a survivor zombie loot drop.
Whitespace killa.
Tweaks a few clothing volumes.

Denim shorts, wool sweater, sports jersey.
Move all the item-processing into the item class.

This combines the item processing done for items on the map and for items that are in the players inventory.
Adds two new house layouts to map generation
Merge pull request #9018 from Rivet-the-Zombie/clothing-volume

Tweaks a few clothing volumes.
Merge pull request #9017 from Rivet-the-Zombie/bigun

Craftable hand-cranked autoshotgun.
fixed scrolling in keybinding window
Ant-glare treatment for ballistic glasses.

Turns out it's far harder to find nontinted ones than tinted ones.
Merge pull request #9033 from Rivet-the-Zombie/ballistic-glasses-tweak

Anti-glare treatment for ballistic glasses.
try again to add morphine
try again to add shopping bags
Pine tree fix.
RM11B marksman rifle.

This was the only category of firearm missing from the caseless line.
Ten round magazine, much improved range for the normally short-range 8mm
rounds, two round burst mode, rather large but not incredibly heavy.
Spawns in military rifle places.