Use id as proxy sorting column for created_at in Explore > Groups

What does this MR do and why?

Use id as the column used to sort by creation date on Explore > Groups (Vue) page. This is necessary to unblock the rollout for the frontend changes while we look for ways to fix the performance issues with the created_at column.

• We have an existing recommendation to use order_by id over order_by created_at when possible. The potential inaccuracy outweighs the performance boost.
  • As noted in the docs: there is rarely a case where the user actually cares about the difference between these 2 columns.
  • The accuracy of creation date is not important in this page.
  • There's still a long way for the Cells architecture. The warning won't take effect for a long time.
• We have prior attempts to add the missing index for these columns but were pushed back due to the number of existing index in the namespaces table.

References

• Related Issue: Improve performance when sorting namespaces by ... (#588691)
• Closes #595016 (closed)

Screenshots or screen recordings

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How to set up and validate locally

1. Enable the explore_groups_vue feature flag
2. Go to http://localhost:3000/explore/groups

MR acceptance checklist

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