feat(redux): Rename all Redux slices and store keys to match file names for clarity

- Renamed all slice names (createSlice `name` attribute) to match their file names (e.g. loopChartSlice, authSlice, kueDataSlice etc.)
- Updated `store.ts` to register each reducer with consistent key names (e.g. state.loopChartSlice instead of state.loopChart)
- Adjusted all `useSelector` and Redux state accesses across the codebase
- Improves maintainability, searchability and consistency across files and Redux DevTools

components/main/settingsPageComponents/OPCUAInterfaceSettings.tsx

@@ -12,7 +12,9 @@ import {
 
 export default function OPCUAInterfaceSettings() {
   const dispatch = useDispatch();
-  const opcuaSettings = useSelector((state: RootState) => state.opcuaSettings);
+  const opcuaSettings = useSelector(
+    (state: RootState) => state.opcuaSettingsSlice
+  );
 
   // Lokale Zustände für das neue Benutzerformular
   const [newUsername, setNewUsername] = useState("");