Random spawn (#2375)

## Description:

https://github.com/openfrontio/OpenFrontIO/issues/2352

This is my first PR in this project, and I’ll continue refining it based
on feedback.

<img width="1088" height="859" alt="image"
src="https://github.com/user-attachments/assets/07f4f8b1-52fa-4136-add4-19b00aefd963"
/>

<img width="1157" height="783" alt="image"
src="https://github.com/user-attachments/assets/1c5be80d-72f8-4ead-8d4b-706a3a04fd73"
/>

<img width="1488" height="777" alt="image"
src="https://github.com/user-attachments/assets/4d743548-f0c3-4579-963b-43676f68fab1"
/>

<img width="1499" height="778" alt="image"
src="https://github.com/user-attachments/assets/f808e44f-ef97-467f-9e41-812e2857c36e"
/>


## 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
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

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

nikolaj_mykola

---------

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

src/server/GameManager.ts

@@ -56,6 +56,7 @@ export class GameManager {
         infiniteTroops: false,
         maxTimerValue: undefined,
         instantBuild: false,
+        randomSpawn: false,
         gameMode: GameMode.FFA,
         bots: 400,
         disabledUnits: [],

src/server/GameServer.ts

@@ -115,6 +115,9 @@ export class GameServer {
     if (gameConfig.instantBuild !== undefined) {
       this.gameConfig.instantBuild = gameConfig.instantBuild;
     }
+    if (gameConfig.randomSpawn !== undefined) {
+      this.gameConfig.randomSpawn = gameConfig.randomSpawn;
+    }
     if (gameConfig.gameMode !== undefined) {
       this.gameConfig.gameMode = gameConfig.gameMode;
     }

src/server/MapPlaylist.ts

@@ -95,6 +95,7 @@ export class MapPlaylist {
       infiniteTroops: false,
       maxTimerValue: undefined,
       instantBuild: false,
+      randomSpawn: false,
       disableNPCs: mode === GameMode.Team && playerTeams !== HumansVsNations,
       gameMode: mode,
       playerTeams,