Add termination (Kündigung) functionality and related translations

- Implemented the ability to initiate terminations from Mietverhältnisse.
- Added new fields and options for terminations in both German and English language files.
- Updated metadata definitions to include relationships for terminations with Mietobjekte and Beteiligte.
- Enhanced the service layer to handle termination creation, including linking relevant entities and copying documents.
- Updated configuration timestamps for deployment.

custom/Espo/Custom/Resources/metadata/entityDefs/CMietobjekt.json

@@ -157,6 +157,14 @@
             "entity": "CMietinkasso",
             "audited": false,
             "isCustom": true
+        },
+        "kndigungen": {
+            "type": "hasMany",
+            "relationName": "cMietobjektKuendigung",
+            "foreign": "mietobjekte",
+            "entity": "CKndigung",
+            "audited": false,
+            "isCustom": true
         }
     },
     "collection": {