Add heir selection functionality in Falukant module

- Implemented getPotentialHeirs and selectHeir methods in FalukantService to allow users to retrieve and select potential heirs based on specific criteria.
- Updated FalukantController to wrap new methods with user authentication and added corresponding routes in FalukantRouter.
- Enhanced OverviewView component to display heir selection UI when no character is present, including loading states and error handling.
- Added translations for heir selection messages in both German and English locales to improve user experience.

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

@@ -206,6 +206,39 @@
                 }
             }
         },
+        "overview": {
+            "title": "Falukant - Overview",
+            "metadata": {
+                "title": "Personal",
+                "name": "Name",
+                "money": "Wealth",
+                "age": "Age",
+                "mainbranch": "Home City",
+                "nobleTitle": "Status"
+            },
+            "productions": {
+                "title": "Productions"
+            },
+            "stock": {
+                "title": "Stock"
+            },
+            "branches": {
+                "title": "Branches",
+                "level": {
+                    "production": "Production",
+                    "store": "Store",
+                    "fullstack": "Production with Store"
+                }
+            },
+            "heirSelection": {
+                "title": "Character Lost - Select Heir",
+                "description": "Your character was lost due to an error. Please select an heir from your main region to continue.",
+                "loading": "Loading potential heirs...",
+                "noHeirs": "No suitable heirs were found.",
+                "select": "Select as Heir",
+                "error": "Error selecting heir."
+            }
+        },
         "nobility": {
             "cooldown": "You can only advance again on {date}."
         },