Support 64-bit hash

[felixwang9817]

The Redis online store implementation currently uses the murmur3 32-bit hash. As noted in this discussion, there is a reasonably high chance of collisions when using 32-bit hashes (this has nothing to do with the murmur3 implementation). Feast should support 64-bit hashes.

[achals]

This would probably require a bump in the entity_key_serialization_version since the hash change would be non-backwards-compatible.

[flyingclouds1985]

I think the fix may not need to be backwards-compatible. the keys in redis will be different anyway (the old entity in cache will expire naturally), the fix just needs both offline-writing&online-fetching being consistent.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.