feat: added code review suggestion

Author: r1b2ns

BDKSwiftExampleWallet/View Model/WalletViewModel.swift

@@ -39,6 +39,9 @@ class WalletViewModel {
     var transactions: [CanonicalTx]
     var walletSyncState: WalletSyncState
     var walletViewError: AppError?
+    var needsFullScan: Bool {
+        bdkClient.needsFullScan()
+    }
 
     private var updateProgress: @Sendable (UInt64, UInt64) -> Void {
         { [weak self] inspected, total in