Implement cooldown feature for nobility advancement

- Added logic in FalukantService to calculate the next available advancement date based on the user's last advancement.
- Updated the frontend to display a cooldown message indicating when the user can next advance in nobility.
- Enhanced the NobilityView component to handle and format the next advancement date appropriately.

frontend/src/i18n/locales/de/falukant.json

@@ -538,7 +538,8 @@
             },
             "advance": {
                 "confirm": "Aufsteigen beantragen"
-            }
+            },
+            "cooldown": "Du kannst frühestens wieder am {date} aufsteigen."
         },
         "reputation": {
             "title": "Reputation",

frontend/src/i18n/locales/en/falukant.json

@@ -41,6 +41,9 @@
                 "raft": "Raft",
                 "sailing_ship": "Sailing ship"
             }
+        },
+        "nobility": {
+            "cooldown": "You can only advance again on {date}."
         }
     }
 }