Add transaction signing functionality to App component

- Introduced a new button to sign transactions, allowing users to generate a signature for a predefined raw transaction.
- Updated state management to handle the transaction signature and display it in the UI.
- Enhanced connection logic to ensure the user's address is retrieved before signing.
- Modified the WalletStore to improve transaction status handling during updates.

src/helpers.ts

@@ -14,6 +14,9 @@ export const parseSignedTxFromStartParam = (webApp: WebApp): SignTransactionResu
     if (!startParam) return null;
   
     const result = decodeResult(startParam);
+    if ('id' in result) {
+        result.id = Number(result.id);
+    }
     return 'signedTx' in result ? result : null;
 };