added an alert dialog function call in context extension

lib/utils/context_extension.dart

@@ -43,4 +43,13 @@ extension ContextExtension on BuildContext {
       },
     );
   }
+
+  void customAlertDialog({required Widget child, required double height}) {
+    showDialog(
+      context: this,
+      builder: (BuildContext context) {
+        return Dialog(child: SizedBox(height: height, child: child));
+      },
+    );
+  }
 }