Fix cluster slot calculation for String keys with DBCS charsets

[ansn366]

Summary

• Make JedisClusterCRC16.getSlot(String) delegate to the byte-array slot calculation after SafeEncoder encoding
• Add a GBK regression test to ensure String and binary APIs compute the same cluster slot when encoded bytes contain hash tag delimiters

Fixes #4685.

Verification

• Compiled the affected Jedis utility classes with JDK 8
• Ran an offline GBK slot verification; result: OK 16212
• Maven test command was attempted, but dependency download was blocked by the sandbox network policy

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Note

Medium Risk
Touches cluster slot routing, so a mistake can send keys to the wrong node. The change is small and covered by a charset-specific test.

Overview
Fixes Redis Cluster slot calculation for String keys when a non-UTF-8 charset (e.g. GBK) is in use.

JedisClusterCRC16.getSlot(String) no longer extracts hash tags on Java characters. It encodes with SafeEncoder and reuses the byte-array path, so {/} are detected on the same bytes Redis would see. A GBK regression test checks String and binary APIs agree (slot 16212).

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