Add typehints

src/primaite/nodes/node.py

@@ -17,7 +17,7 @@ class Node:
         priority: Priority,
         hardware_state: HardwareState,
         config_values: TrainingConfig,
-    ):
+    ) -> None:
         """
         Initialise a node.
 

src/primaite/nodes/node_state_instruction_green.py

@@ -18,7 +18,7 @@ class NodeStateInstructionGreen(object):
         _node_pol_type: "NodePOLType",
         _service_name: str,
         _state: Union["HardwareState", "SoftwareState", "FileSystemState"],
-    ):
+    ) -> None:
         """
         Initialise the Node State Instruction.