feat: add request cancellation functionality

lib/screens/home_page/editor_pane/details_card/response_pane.dart

@@ -27,6 +27,14 @@ class ResponsePane extends ConsumerWidget {
     if (responseStatus == null) {
       return const NotSentWidget();
     }
+
+    if (message == "Request Cancelled") {
+      return ErrorMessage(
+        message: '$message',
+        showIssueButton: false,
+      );
+    }
+
     if (responseStatus == -1) {
       return ErrorMessage(message: '$message. $kUnexpectedRaiseIssue');
     }

lib/screens/home_page/editor_pane/url_card.dart

@@ -127,6 +127,11 @@ class SendRequestButton extends ConsumerWidget {
             .read(collectionStateNotifierProvider.notifier)
             .sendRequest(selectedId!);
       },
+      onCancel: () {
+        ref
+            .read(collectionStateNotifierProvider.notifier)
+            .cancelRequest(selectedId!);
+      },
     );
   }
 }