Add device property to PyLimeConfig

Introduced a getter and setter for the 'device' property, allowing for
UTF-8 encoding/decoding of the device string in the PyLimeConfig class.
This enhances string handling consistency across the interface.

src/limedriver/limedriver.pyx

@@ -660,6 +660,14 @@ cdef class PyLimeConfig:
             self._config.c3_synth[i] = values[i]
  
     # String properties
+    @property
+    def device(self):
+        return self._config.device.decode('utf-8')
+    
+    @device.setter
+    def device(self, str value):
+        self._config.device = value.encode('utf-8')
+
     @property
     def file_pattern(self):
         return self._config.file_pattern.decode()