Indicate user was banned only when auto-ban setting is enabled

Resolves: https://gitlab.com/gitlab-org/modelops/anti-abuse/team-tasks/-/issues/46

What does this MR do and why?

Update the email sent to application admins and namespace owners to indicate that the user was auto-banned only when auto-ban setting is enabled.

Screenshots or screen recordings

auto-ban enabled	auto-ban disabled

How to set up and validate locally

Validate that email contains correct contents when a user exceeds application-wide projects download throttling threshold

1. Configure application-wide projects download throttling:

   $ rails console
   > ApplicationSetting.first.update({
      max_number_of_repository_downloads: 1,
      max_number_of_repository_downloads_within_time_period: 60,
      auto_ban_user_on_excessive_projects_download: true
   })

2. Create a private top-level group and two projects under the group
3. Add a user as a developer to the group
4. Execute Users::Abuse::ExcessiveProjectsDownloadBanService for each project

   > rails console
   > user = User.find(<id_of_developer_user>)
   > project1 = Project.find(<id_of_first_project>)
   > project2 = Project.find(<id_of_second_project>)
   > Users::Abuse::ExcessiveProjectsDownloadBanService.execute(user, project1)
   => {:banned=>false}
   > Users::Abuse::ExcessiveProjectsDownloadBanService.execute(user, project2)
   => {:banned=>true}

5. Check the sent email in http://localhost:3000/rails/letter_opener
6. Validate that the email indicates the user was auto-banned
   📸

   
7. Unban the user

   > rails console
   > User.find(<id_of_developer_user>).unban
   => true

8. Disable auto-banning

   $ rails console
   > ApplicationSetting.first.update({ auto_ban_user_on_excessive_projects_download: false })

9. Execute Users::Abuse::ExcessiveProjectsDownloadBanService for each project

   > rails console
   > user = User.find(<id_of_developer_user>)
   > project1 = Project.find(<id_of_first_project>)
   > project2 = Project.find(<id_of_second_project>)
   > Users::Abuse::ExcessiveProjectsDownloadBanService.execute(user, project1)
   => {:banned=>false}
   > Users::Abuse::ExcessiveProjectsDownloadBanService.execute(user, project2)
   => {:banned=>false}

10. Check the sent email in http://localhost:3000/rails/letter_opener
11. Validate that the email does not indicate the user was auto-banned
    📸

    

Validate that email contains correct contents when a user exceeds namespace-wide projects download throttling threshold

1. Create a private top-level group and two projects under the group
2. Configure namespace-wide projects download throttling:

   $ rails console
   > group = Group.find(<id_of_your_group>)
   > group.namespace_settings.update({
       unique_project_download_limit: 1,
       unique_project_download_limit_interval_in_seconds: 60,
       auto_ban_user_on_excessive_projects_download: true
     })

3. Add a user as a developer to the group
4. Execute Users::Abuse::GitAbuse::NamespaceThrottleService for each project

   > rails console
   > user = User.find(<id_of_developer_user>)
   > project1 = Project.find(<id_of_first_project>)
   > project2 = Project.find(<id_of_second_project>)
   > Users::Abuse::GitAbuse::NamespaceThrottleService.execute(project1, user)
   => {:banned=>false}
   > Users::Abuse::ExcessiveProjectsDownloadBanService.execute(project2, user)
   => {:banned=>true}

5. Check the sent email in http://localhost:3000/rails/letter_opener
6. Validate that the email indicates the user was auto-banned
   📸

   
7. Unban the user

   > rails console
   > ::Namespaces::NamespaceBan.destroy_all

8. Disable auto-banning

   $ rails console
   > group = Group.find(<id_of_your_group>)
   > group.namespace_settings.update({
       auto_ban_user_on_excessive_projects_download: false
     })

9. Execute Users::Abuse::GitAbuse::NamespaceThrottleService for each project

   > rails console
   > user = User.find(<id_of_developer_user>)
   > project1 = Project.find(<id_of_first_project>)
   > project2 = Project.find(<id_of_second_project>)
   > Users::Abuse::GitAbuse::NamespaceThrottleService.execute(project1, user)
   => {:banned=>false}
   > Users::Abuse::ExcessiveProjectsDownloadBanService.execute(project2, user)
   => {:banned=>false}

10. Check the sent email in http://localhost:3000/rails/letter_opener
11. Validate that the email does not indicate the user was auto-banned
    📸

    

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.