Customize Service Desk issue confidentiality

Problem to solve

An organization desires to default issues created by Service Desk to non-confidential so that they can be visible by anyone with access to the project.

Intended users

This feature would be used by organizations where issues created by the Service Desk should be viewable to all who have access to the project.

Proposal

Allow the confidentiality to be user configurable. This would be defaulted to confidential so there is no change to the current behavior, but would give users the option of configuring this setting.

From #33091 (comment 1869534107)

1. Introduce new feature flag service_desk_tickets_confidentiality.
2. Add a new db field tickets_confidential_by_default in service_desk_setting to store whether issues/tickets should be confidential (default:true). I'd go with this name because in issues we use confidential: true|false so it feels more descriptive to use tickets_confidential_by_default instead of tickets_public_by_default.
3. Add a checkbox to the Service Desk section in the general settings. This setting is only visible or selectable if the project is either private or internal. It's not available for public projects as this may expose confidential information to unauthenticated users.
4. In the email/issue processing only mark a new issue/ticket as not confidential if it's not public and the tickets_confidential_by_default is false.

Permissions and Security

TBD

Documentation

Documentation for the configuration options would need to be updated.

Testing

TBD

What is the type of buyer?

This would only be available for those users who have existing access to the Service Deks.

Links / references