[Feature] Federate metadata

Requirements

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Is your proposal related to a problem?

I always assumed my Lemmy instance was only making connections to other instances, but its constantly making GET requests to all kinds of non-Lemmy webservers for scraping.

I am not sure if Im too happy about that, for example Reddit may rate-limit my IP, other websites might block me for constant scraping and it might connect to all kinds of shady or illegal websites. Also, if the number of instances grows, that would trigger a DoS attack at the external URL by all those instances fetching the metadata at roughly the same time.

Could there be an option to disable metadata scraping for federated posts? I dont mind my server connecting to other Lemmy servers, I just want it to trust the received metadata (thumbnail url and summary) instead of crawling the whole web just to verify it. For local posts the metadata fetching is fine.

Describe the solution you'd like.

A setting to disable the fetching of metadata for federated (remote) posts, and trust those fields from the remote instance.

Describe alternatives you've considered.

N/A

Additional context

No response