Reorder exported relations by primary_key

What does this MR do?

This MR fixes the order of exported relations when using Group/Project Export. It ensures that the order of relations is always by it's primary key and each relation is in consistent order.

Reason for change: Pipelines bug where pipelines order is reversed. #27883 (closed) Originally this was fixed by sorting pipelines on Import, however a better solution is to have consistent ordering of every relation on Export instead.

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Does this MR meet the acceptance criteria?

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