WIP: Change default sorting in branches API to the last updated date

What does this MR do?

Change default sorting in branches API to updated_desc.

This leads into showing the most recent branch first as with the MR filter API.

Alternative implementation

In the issue the proposal is to return the default branch at first but this change instead leads to an API consistent with the MR filter API (linked in the related issue) and it's also a simple change. Moreover this change leads into very likely returning the default_branch on top.

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability 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
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

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

Related to #220990 (closed)