Enhance Keenetic model and update templates for improved data handling

- Implemented the `interfaces` and `vlans` methods in the `Keenetic` model to process and decode interface and VLAN data.
- Added a `_decode_utf` method to handle UTF-8 encoded descriptions.
- Updated the Keenetic TTP template to define structured groups for system, interfaces, and VLANs.
- Refactored file paths in the `Mikrotik` model for consistency and clarity.

oxi/interfaces/base.py

@@ -106,7 +106,7 @@ class BaseDevice(ABC):
             raise ValueError(
                 f"{self.__class__.__name__}: TTP template '{self.template}' "
                 f"did not produce required sections: {sorted(missing)}. "
-                f"Got: {sorted(raw.keys())}"
+                f"Got: {(raw.keys())}"
             )
         return raw