feat(gui, tauri): Accept --testnet flag, default to mainnet (#106)

This PR tackles #92 

- Add the `tauri-plugin-cli` (only on desktop)
- Check in the frontend if the `--testnet` flag is set. If it's set we pass `testnet=true` to the `initialize_context` command on invokation
- We add the `vite-plugin-top-level-await` to allow top level await in all browsers
- Remove the `bitcoin_confirmation_target` from settings for simplicity

src-gui/src/renderer/components/modal/swap/SwapDialog.tsx

@@ -31,11 +31,12 @@ export default function SwapDialog({
   onClose: () => void;
 }) {
   const classes = useStyles();
+
   const swap = useAppSelector((state) => state.swap);
   const isSwapRunning = useIsSwapRunning();
-
   const [debug, setDebug] = useState(false);
   const [openSuspendAlert, setOpenSuspendAlert] = useState(false);
+
   const dispatch = useAppDispatch();
 
   function onCancel() {