More name, weight, and volume updates

[KorGgenT]

Summary

Purpose of change

The purpose of this change is to increase consistency of our Json, and to perhaps deprecate the old style at some point later on.
For names, we use the translation object, which is like so: { "str": string, "str_pl": string }
for volumes, we want to use units strings, and try to keep to larger units when possible:
"750 ml" or "1 L"
similar for weights:
"899 g" or "4 kg" or "28 mg"

Describe the solution

go through the json definitions in the following files:

• monsters\insect_spider.json
• monsters\marloss.json
• monsters\mechsuits.json
• monsters\mi-go.json
• monsters\mutant.json

Testing

Loaded the game, observe no errors. then view a couple of entries from each file to see that the name displays properly. Spawn in a few of these and kill them, observing that their corpses did not change in volume or weight.