Germany (#4559)

Resolves #4558 

## Description:
Sets 1 pixel on the Oder river to be water to allow trade to flow
through
Sets 1 pixel on the left side of the Oder to be land and not impassable

<img width="730" height="1197" alt="Screenshot 2026-07-09 203514"
src="https://github.com/user-attachments/assets/5f711ea3-0e92-467b-b030-1099c6c8a97e"
/>


## 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:

Lengy_

resources/maps/germany/manifest.json

@@ -3,7 +3,7 @@
   "id": "Germany",
   "map": {
     "height": 1516,
-    "num_land_tiles": 1072927,
+    "num_land_tiles": 1072928,
     "width": 1548
   },
   "map16x": {
@@ -13,7 +13,7 @@
   },
   "map4x": {
     "height": 758,
-    "num_land_tiles": 265158,
+    "num_land_tiles": 265159,
     "width": 774
   },
   "multiplayer_frequency": 5,