fix: General improvements on purchase restore

Sources/Earthquake Network/Controllers/InApp/SubscriptionsViewController.swift

@@ -40,6 +40,8 @@ class SubscriptionsViewController: UITableViewController {
     private var availability: EQNPurchaseAvailability?
     /// Tells if products are loading
     private var isLoading = false
+    /// Tells if a restore is in progress
+    private var isRestorePurchase = false
     
     // MARK: - View Lifecycle
     
@@ -155,7 +157,8 @@ class SubscriptionsViewController: UITableViewController {
     // MARK: - Actions
     
     @objc func restoreTapped(_ sender: AnyObject) {
-      VersioneProProducts.store.restorePurchases()
+        isRestorePurchase = true
+        VersioneProProducts.store.restorePurchases()
     }
     
     // MARK: - Notifications
@@ -165,6 +168,15 @@ class SubscriptionsViewController: UITableViewController {
     }
     
     @objc func handlePurchaseNotification(_ notification: Notification) {
+        if isRestorePurchase {
+            isRestorePurchase = false
+            
+            let alert = UIAlertController(title: NSLocalizedString("purchase_pro_restore_alert_title", comment: ""),
+                                          message: NSLocalizedString("purchase_pro_restore_alert_message", comment: ""), preferredStyle: .alert)
+            alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
+            present(alert, animated: true, completion: nil)
+        }
+        
         VersioneProProducts.store.loadPurchase()
         loadData()
     }