Add CMietinkasso entity and localization support

- Introduced a new entity "CMietinkasso" with its metadata definitions, including fields, links, and indexes.
- Added controller for CMietinkasso to handle business logic.
- Created localization files for CMietinkasso in multiple languages (e.g., English, German, Spanish, etc.) to support internationalization.
- Updated global JSON files to include references to the new entity.
- Modified configuration files to integrate CMietinkasso into the application structure.

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

@@ -12,7 +12,8 @@
                 "CVmhErstgespraech",
                 "CVmhVermieter",
                 "CBeteiligte",
-                "CCallQueues"
+                "CCallQueues",
+                "CMietinkasso"
             ]
         }
     }