Adds four new Unathi drinks (#21393)

## About PR
This PR adds four new Unathi related drinks and reflavours most of the
existing ones to be less of weird wordplays and jokes.
Requested by the Unathi team.
The new drinks and bottle sprite can be seen below. Please enjoy:
> <img width="547" height="102" alt="image"
src="https://github.com/user-attachments/assets/c2122a83-eccd-4b46-b57a-089e6d81704c"
/>
Tested (hopefully) all changes. Works on my machine. 👍 

### Asset Licenses
The following assets that **have not** been created by myself are
included in this PR:

| Path | Original Author | License |
| --- | --- | --- |
| icons/obj/drinks.dmi | Captain Gecko (AuroraStation) | CC0 |
| icons/obj/reagent_containers/food/drinks/bottle..dmi | Captain Gecko
(AuroraStation) | CC0 |

code/modules/reagents/reagent_containers/food/drinks/bottle.dm

@@ -1061,6 +1061,13 @@
 	center_of_mass = list("x" = 16,"y" = 6)
 	reagents_to_add = list(/singleton/reagent/alcohol/butanol/sarezhiwine = 100)
 
+/obj/item/reagent_containers/food/drinks/bottle/redstaff
+	name = "Redstaff"
+	desc = "Less of a unique spirit and instead a mixture of butanol, spices, and algae; either Gukhe bloom, Koko, or whatever is at hand when making it. The end result is a fairly strong drink with a spicy kick. \
+	Though it’s more used as a cocktail ingredient rather than drank by itself."
+	icon_state = "redstaff"
+	reagents_to_add = list(/singleton/reagent/alcohol/butanol/redstaff = 100)
+
 // Synnono Meme (Bottled) Drinks
 //======================================
 //