Adds Map of China (#4468)

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improvements as
[issues](https://github.com/openfrontio/OpenFrontIO/issues/new/choose).
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**Add approved & assigned issue number here:**

Resolves #4419

## Description:

- Adds a China Map. This is themed after Qing China from the late 19th
and early 20th centuries, which is why the map also includes Mongolia
and Taiwan.
- There are 32 nations themed after qing provinces, warlords, factions,
European colonies, rebellions.
- Also adds several new flags: EastTurkestan, Manchukuo,
BritishHongKong, TaipingHeavenlyKingdom, etc.
- Includes additional nations for a total of 62 nations.
- Size: 1892x2080
- Land area: approx. 1.86M
- Adds Caspian Sea and China to the new category (which i forgot
earlier)


https://youtu.be/ew9Qizo67cA

<img width="2082" height="1895" alt="image"
src="https://github.com/user-attachments/assets/d34fbb9e-fa93-4afe-a89f-8f11c5f9529b"
/>


## 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:

DISCORD_USERNAME crunchybbbbb

src/core/game/Maps.gen.ts

@@ -27,6 +27,7 @@ export enum GameMapType {
   Caribbean = "Caribbean", // map-generator/assets/maps/caribbean/info.json
   CaspianSea = "Caspian Sea", // map-generator/assets/maps/caspiansea/info.json
   Caucasus = "Caucasus", // map-generator/assets/maps/caucasus/info.json
+  China = "China", // map-generator/assets/maps/china/info.json
   ChoppingBlock = "Chopping Block", // map-generator/assets/maps/choppingblock/info.json
   Conakry = "Conakry", // map-generator/assets/maps/conakry/info.json
   DanishStraits = "Danish Straits", // map-generator/assets/maps/danishstraits/info.json
@@ -327,7 +328,7 @@ export const maps: readonly MapInfo[] = [
     id: "CaspianSea",
     type: GameMapType.CaspianSea,
     translationKey: "map.caspiansea",
-    categories: ["asia"],
+    categories: ["asia", "new"],
     multiplayerFrequency: 5,
   },
   {
@@ -337,6 +338,13 @@ export const maps: readonly MapInfo[] = [
     categories: ["europe", "asia"],
     multiplayerFrequency: 5,
   },
+  {
+    id: "China",
+    type: GameMapType.China,
+    translationKey: "map.china",
+    categories: ["asia", "countries", "new"],
+    multiplayerFrequency: 8,
+  },
   {
     id: "ChoppingBlock",
     type: GameMapType.ChoppingBlock,