Fix difference in translation strings regarding the new Between Two Seas map (#416)

##Description:
I renamed all instances of "TwoSeas" to "BetweenTwoSeas". That way it
lowers the confusion but more importrantly - it removes the difference
between the translation strings for the map.

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

<Nikola123>

src/core/configuration/DefaultConfig.ts

@@ -95,9 +95,11 @@ export abstract class DefaultServerConfig implements ServerConfig {
     }
     // Maps smaller than ~2 mil pixels
     if (
-      [GameMapType.TwoSeas, GameMapType.BlackSea, GameMapType.Pangaea].includes(
-        map,
-      )
+      [
+        GameMapType.BetweenTwoSeas,
+        GameMapType.BlackSea,
+        GameMapType.Pangaea,
+      ].includes(map)
     ) {
       return Math.random() < 0.2 ? 60 : 35;
     }