Quick actions - error/success messages

We should improve how we handle success/error messages when using quick actions. Specifically the problem is with quick actions that use the predefined update services (@updates).

We define the success message in classes located in https://gitlab.com/gitlab-org/gitlab/-/tree/master/lib/gitlab/quick_actions in execution_message. The problem is that when we use @updates we basically don't know about the success/failure and therefore display just a generic message.

We should fix that.

There are probably 2 parts of this issue:

1. Handling errors when using the quick action from the issue (MR, epic) description
2. Handling errors when using system notes

Examples: /due_date, /add_contact