completed migrating data scope from user to workspace

lib/screens/groups/models/recipient_group_model.dart

@@ -9,6 +9,7 @@ class RecipientGroup {
   final String name;
   final String? description;
   final String? userId;
+  final String? workspaceId;
   final String? createdAt;
 
   const RecipientGroup({
@@ -16,6 +17,7 @@ class RecipientGroup {
     required this.name,
     this.description,
     this.userId,
+    this.workspaceId,
     this.createdAt,
   });
 
@@ -56,12 +58,14 @@ class CreateGroupRequest {
   final String name;
   final String? description;
   final String userId;
+  final String workspaceId;
   final List<Recipient> recipients;
 
   const CreateGroupRequest({
     required this.name,
     this.description,
     required this.userId,
+    required this.workspaceId,
     required this.recipients,
   });