Modernize more volume and weight

[hexagonrecursion]

Summary

SUMMARY: none

Purpose of change

Contributes to #36110

Describe the solution

Convert the integral_volume and the confusingly named barrel_length to strings

Describe alternatives you've considered

none

Testing

1. Create a new world with the following mods:

• Disable NPC Needs
• CRIT Expansion
• Generic Guns
• Magiclysm

2. Start a new game in it
3. Test that attaching a tactical flashlight (id: flash_acc) to Luty SMG: .40 S&W (id: smg_40) does not change the volume of the SMG
4. Test that a sawn-off handmade magnum carbine is 0.25 L smaller than a regular one

Additional context

This PR was brought to you by

#!/usr/bin/env bash
set -eux

echo "Using JSON formatter: ${JSON_FORMATTER:=tools/format/json_formatter.cgi}"
echo

# The data/ directory is a mess:
# 1. It has a json/ subdirectory even though there is plenty of JSON
#    outside that subdirectory.
# 2. Most JSON files in data/ have a uniform structure (see example 1 below),
#    but there are exceptions - files that have a completely different structure.
# The following command collects the names of all the files that use the uniform
# structure ignoring all files that don't. It also looks in utilities/.
# Even though utilities/ does not contain any loadable data, it contains
# examples. I want to modernize the documentation too.
#
# example 1
# [
#   {"type": "foo", ...},
#   {"type": "bar", ...}
# ]
#
mapfile -t FILES < <(
	find utilities data \
		-name '*.json' \
		-not -path 'data/raw/color_templates/no_bright_background.json' \
		-not -path 'data/names/*' \
		-not -path 'data/mods/replacements.json' \
		-not -path 'data/fontdata.json' \
)

# Piping game data through jq introduces some noise because jq does not
# distinguish between 123.0 and 123. I use some git rebase magic
# to work around this issue. After running this script run:
# git rebase --onto=master modernize-volume-weight-noise modernize-volume-weight-2
git checkout -b modernize-volume-weight-noise master
for F in "${FILES[@]}"; do
	echo "noise: $F"
	jq '.' "$F" | $JSON_FORMATTER | sponge "$F"
done
git add .
git commit -m 'DO NOT MERGE'

JQ='
(
  .[]
  |
    (select(.type=="GUN") | .barrel_length),
    (select(.type=="GUNMOD") | .integral_volume)
  | numbers
) |= (./4*1000 | if .%1000 == 0 then "\(./1000) L" else "\(.) ml" end)
'
git checkout -b modernize-volume-weight-2 modernize-volume-weight-noise
for F in "${FILES[@]}"; do
	echo "$F"
	jq "$JQ" "$F" | $JSON_FORMATTER | sponge "$F"
done
git add .
git commit -m 'Modernize more volume and weight'