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/CDokumente.json

@@ -176,6 +176,14 @@
             "audited": false,
             "isCustom": true
         },
+        "kndigungensdokumente": {
+            "type": "hasMany",
+            "relationName": "cDokumenteKuendigung",
+            "foreign": "dokumenteskuendigung",
+            "entity": "CKndigung",
+            "audited": false,
+            "isCustom": true
+        },
         "beteiligte2dokumente": {
             "type": "hasMany",
             "relationName": "cBeteiligteDokumente",