Show Upcoming Status for Releases

What does this MR do?

Add a released_at column to the releases table. Backfill this column with the value from the created_at column.

Allow the Releases API to take a date/time value and save the value in the released_at column.

If the released_at value is not supplied in the request to create a release, fill it with the current date/time. This will prevent breaking existing scripts using the API that may not provide the parameter.

Return releases to the API sorted by released_at rather than by created_at.

Return an upcoming_release boolean field to the Releases API. true for a released_at in the future, false for a past released_at.

Related issue: #38105 (closed)

Example of Upcoming Releases in the UI:

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

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

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team