FR: Sync with ICloud service

[simulot]

The use case:

From looper33 on discord:

I have my cron job going every 6 hours pushing photos downloaded by icloudpd to immich. So, it runs 4 times a day for me, thank you very much. I honestly have yet to hear/understand how people who have tens of thousands of icloud photos use immich to keep icloud photo library mirror ( besides the workflow I devised) , since the immich ios client can't possibly ever complete with dedup'ing huge libraries (most of which aren't even local to the phone, so have to be pulled from icloud, then pushed to immich server, and better hope
immich is foregrounded because if it's backgrounded on ios, you get a couple of cpu cycles an hour, lol)

To save bandwidth, CPU and storage, it would be nice to synchronise only recent photos.