Notifications: Email alerts for eval completion

[Ayush8923]

Is your feature request related to a problem?
Currently, users associated with a project do not receive notifications when an eval run completes. They have to manually check the platform, which is inconvenient for long-running eval workflows.

Describe the solution you'd like

• Trigger notification only after an eval run is completed.
• Fetch all users associated with the project.
• Send an email notification to all project users.
• Include relevant details in the email:
  • Eval name
  • Project name
  • Completion status
  • Completion timestamp
  • Link to view eval results
• Ensure duplicate emails are not triggered.
• Add proper logging for the notification flow.
• Handle failed email delivery gracefully.

Original issue

Describe the current behavior
Implement email notifications for eval runs so that all users associated with a project are notified once an eval execution is completed. Currently, users need to manually check the platform to know whether an eval has completed, which is inconvenient for long-running eval workflows.

Describe the enhancement you'd like

• Trigger notification only after an eval run is completed.
• Fetch all users associated with the corresponding project.
• Send an email notification to all connected project users.
• Include relevant details in the email:
  • Eval name
  • Project name
  • Completion status
  • Completion timestamp
  • Link to view eval results
• Ensure duplicate emails are not triggered.
• Add proper logging for the notification flow.
• Handle failed email delivery gracefully.

Why is this enhancement needed?

• All users connected to the project receive an email after eval completion.
• Email contains eval details and result link.
• Notification is triggered only once per completed eval run.