[SVC-1666] Prewarm ATS cache when deploying a new version

[NathanFlurry]

Motivation

Booting new lobbies right after deploying a new version requires a long wait time because the node has to download the image directly from S3.

Prewarming the cache will save the image to the cache before trying to boot any lobbies.

This is blocked by using consistent_hash in ATS because this will also change the ATS architecture.

Implementation

• List all ATS nodes from Consul for the version's regions
• Make a request for the asset
• Wait for it to complete & handle failure gracefully

_{From SyncLinear.com | SVC-1666}

[NathanFlurry]

Out of sync with Linear