feat: Add termination functionality for rental agreements

- Introduced new entity `CKuendigung` for managing terminations.
- Added fields for termination details including date, reason, type, and status.
- Implemented backend service to initiate terminations from rental agreements.
- Created frontend handler for termination actions with confirmation dialog.
- Updated metadata and layouts for `CKuendigung` to support new functionality.
- Added internationalization support for English and German languages.
- Enhanced existing entities to establish relationships with terminations.

custom/Espo/Custom/Resources/metadata/layouts/CKuendigung/detailSmall.json

@@ -0,0 +1,40 @@
+[
+    [
+        {
+            "name": "name"
+        },
+        {
+            "name": "status"
+        }
+    ],
+    [
+        {
+            "name": "kuendigungsart"
+        },
+        {
+            "name": "kuendigenderPartei"
+        }
+    ],
+    [
+        {
+            "name": "kuendigungsdatum"
+        },
+        {
+            "name": "kuendigungsfrist"
+        }
+    ],
+    [
+        {
+            "name": "vmhMietverhltnis"
+        },
+        {
+            "name": "mietobjekt"
+        }
+    ],
+    [
+        {
+            "name": "assignedUser"
+        },
+        false
+    ]
+]