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/store.ts

@@ -90,7 +90,8 @@ export class WalletStore {
 
                     let shouldDispatch = false;
                     dataTransactions.forEach(transaction => {
-                        if (!currentTransactions.find(t => t.id === transaction.id)) {
+                        const currentTransaction = currentTransactions.find(t => t.id === transaction.id);
+                        if (currentTransaction && currentTransaction.status !== transaction.status) {
                             shouldDispatch = true;
                         }
                     });