KIP-190 — Handle client-ids consistently between clients and brokers

Accepted Kafka 1.0 Client

Removes the overly restrictive character whitelist for `client.id` enforced by the Java client, aligning with broker behavior that imposes no such restrictions. The character restrictions prevented third-party clients (e.g., librdkafka) using valid but non-whitelisted client IDs from being handled consistently, causing quota and metric tagging failures.

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