Medical Treatment - Settings to limit IVs to certain locations

[pterolatypus]

When merged this pull request will:

• Adds two settings to limit use of a) saline and b) blood and plasma to specific locations
• Settings are separate to allow more differentiation of the IV types in the future
• Needs translations

Additionally, I noticed that the Treatment subcategory in settings is getting pretty big. Would it be worth moving this to its own category?

[mharis001]

Why keep plasma and blood together while splitting saline? I think it would be better if all three are controlled by one setting or each has their own.

[pterolatypus]

Why keep plasma and blood together while splitting saline?

It was because I plan to write a separate PR changing how the different fluids work, but on second thoughts I can just split them out if and when I actually do that.