feat(useragent): callouts feature for approving new things

useragent/lib/features/callouts/callout_event.dart

@@ -0,0 +1,25 @@
+import 'package:arbiter/proto/client.pb.dart';
+import 'package:freezed_annotation/freezed_annotation.dart';
+import 'package:hooks_riverpod/experimental/mutation.dart';
+
+part 'callout_event.freezed.dart';
+
+@freezed
+sealed class CalloutData with _$CalloutData {
+  const factory CalloutData.connectApproval({
+    required String pubkey,
+    required ClientInfo clientInfo,
+  }) = ConnectApprovalData;
+}
+
+@freezed
+sealed class CalloutEvent with _$CalloutEvent {
+  const factory CalloutEvent.added({
+    required String id,
+    required CalloutData data,
+  }) = CalloutEventAdded;
+
+  const factory CalloutEvent.cancelled({
+    required String id,
+  }) = CalloutEventCancelled;
+}