Add Titan map with random spawn nations - along new Cosmic map category

[RickD004]

Purpose

Adds Titan map

Objectives

Adds "Titan" (real moon of Saturn with methane seas) map . Uses new random spawn nation feature by FloPinguin. #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.

Description

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

titan_teaser-ezgif.com-resize-video.mp4

tri.star1011