Add cross-slot details into redis logs

What does this MR do and why?

This MR runs the RedisClusterValidator in all environments but only raises the error in dev or test environments. It also adds the count of redis_cross_slot_calls into the logline. With this change, we can estimate the volume of cross-slot operations that are being performed right now.

See gitlab-com/gl-infra/scalability#2005

There will be extra fields in kibana after rollout

• redis_cross_slot_calls
• redis_{store name}_cross_slot_calls

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How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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