Adds Gulf of Guinea map (#4590)

## Description:

Adds Gulf of Guinea map to the game:
https://en.wikipedia.org/wiki/Gulf_of_Guinea

Final map of the "pirate maps" for v33 , alongside Irish Sea and Levant.
The map is designed so that all the trade from the mainland, which
covers 2 of the four corners of the "square" (inverse L) passes through
3 small islands, which although small in size they will super-boost
pirates in that zone. The mainland is otherwise fairly lineal, playing
like maps like Conakry.

Also some sub-saharan african representation

The map is decorated with Impassable terrain in its southern border, and
has additional nations for Hvn and Solo games


https://github.com/user-attachments/assets/9c9fd8c0-fefb-46c4-8720-55e90401681e

## 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

resources/lang/en.json

@@ -958,6 +958,7 @@
     "germany": "Germany",
     "giantworldmap": "Giant World Map",
     "greatlakes": "Great Lakes",
+    "gulfofguinea": "Gulf Of Guinea",
     "gulfofstlawrence": "Gulf of St. Lawrence",
     "halkidiki": "Halkidiki",
     "hawaii": "Hawaii",