Add Titan map with random spawn nations - along new Cosmic map category (#4183)

Resolves #4182

## Description:

Adds "Titan" (real moon of Saturn with methane seas) map . Uses new
random spawn nation feature by FloPinguin.
https://github.com/openfrontio/OpenFrontIO/pull/4156

Also adds new Cosmic map category. The "Other" map category has become a
wastebasket of unrelated maps, and with increasing number of maps, i
think its a good addition to have better categories for these maps.

I figured these 2 changes should go together since im adding a cosmic
map, and a cosmic category.

proof of nations spawning randomly and how the cosmic category looks in
the menu:


https://github.com/user-attachments/assets/b84bd3ef-6b8f-46fe-a6ea-ea5e79c6dc00

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory

## Please put your Discord username so you can be contacted if a bug or
regression is found:

tri.star1011

---------

Co-authored-by: Evan <evanpelle@gmail.com>

CREDITS.md

@@ -86,6 +86,11 @@ Ernie Wright (USRA) ORCID logo.
 Scientist
 Noah Petro (NASA/GSFC) ORCID logo.
 
+### Titan Map
+
+[NASA/JPL-Caltech/ASI/USGS](https://science.nasa.gov/photojournal/titans-north/)
+[Public Domain](https://www.nasa.gov/nasa-brand-center/images-and-media/)
+
 ### Antarctica Map
 
 Polar Geospatial Center, 2018, "PGC Map Catalog", https://doi.org/10.7910/DVN/6R8F7U, Harvard Dataverse, V1, [2364], [Apr-02-2026].