Changed CONFIG GET to be sent to a random node

[barshaul]

Removed CONFIG GET from AllNodes request policy and AllSucceeded response policy. CONFIG GET will be sent to a random node.

[nihohit]

Instead of this PR, please just align the request/response policies with the commands tips. You can import redis-rs#887, or revert the change from nihohit@45dc902

Alternatively, better explain this change, because the PR's description doesn't match the code or the change - for example, "CONFIG GET, REWRITE and RESETSTAT don't have a response nor request policy." - they have both, in the repo, since Adan added them (IMO wrongly)

[barshaul]

Instead of this PR, please just align the request/response policies with the commands tips. You can import redis-rs#887, or revert the change from 45dc902

Alternatively, better explain this change, because the PR's description doesn't match the code or the change - for example, "CONFIG GET, REWRITE and RESETSTAT don't have a response nor request policy." - they have both, in the repo, since Adan added them (IMO wrongly)

CONFIG GET, REWRITE and RESETSTAT don't have a response nor request policy in Redis's command tips, which means, in my understanding, we need to decide how to handle them.

It make sense to send all of them to all nodes, as it is suggested to CONFIG SET, and it make sense to apply AllSucceed response policy for RESETSTAT and REWRITE, which just return OKs.
re. Config GET the policy we did is AllNodes for request policy and we leaved it with Special response policy to return all answers.

Do you have a better solution?