Add "New release" to the custom notification (BE)

What does this MR do?

Add "New release" to the custom notification (BE) - Work in progress

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides

Performance and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers - Chrome and Firefox

Closes #26001 (closed)