a8n: Generated diff has not a deterministic order

Created by: eseliger

Steps to reproduce:

1. Generate a campaign preview
2. Generate a campaign preview with the exact same parameters again (need to reload between, if using UI)

Expected behavior:

The output looks exactly the same, also the files are sorted by a natural order

ie. not File1 File3 File2

Actual behavior:

The output order changes sometimes, and the order is random.

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Note: this causes flackiness on the current e2e test. If this takes longer to fix lmk and I will revert the commit for now