Refactor termination and rental object entities

- Removed the "Kündigungen" field from the German and English rental object JSON files.
- Updated the termination JSON files to reflect new field names and structure, including renaming "kuendigungsart" to "beendigungsTatbestand" and "kuendigungsgrund" to "kuendigungsgrund" with updated options.
- Deleted the old "CKuendigung" entity definition and related metadata, consolidating functionality into "CKndigung".
- Adjusted the service logic to accommodate the new structure, ensuring proper linking of landlords and tenants.
- Updated dynamic visibility logic for fields based on conditions related to termination reasons and delivery methods.
- Cleaned up metadata definitions for both termination and rental object entities, removing unnecessary relationships and fields.
- Incremented cache and microtime values in the configuration file.

data/config.php

@@ -360,8 +360,8 @@ return [
     0 => 'youtube.com',
     1 => 'google.com'
   ],
-  'cacheTimestamp' => 1769255131,
-  'microtime' => 1769255131.563756,
+  'cacheTimestamp' => 1769337671,
+  'microtime' => 1769337671.657132,
   'siteUrl' => 'https://crm.bitbylaw.com',
   'fullTextSearchMinLength' => 4,
   'appTimestamp' => 1768843902,