Consistent hashing support server tag

[egolearner]

What problem does this PR solve?

Issue Number:2993

Problem Summary:

What is changed and the side effects?

Changed:

1. 在判断Node是否相同时，依次比较hash/server_addr/tag
2. 在生成hash时，包含tag。

Side effects:

• Performance effects:

• Breaking backward compatibility:

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Check List:

• Please make sure your changes are compilable.
• When providing us with a new feature, it is best to add related tests.
• Please follow Contributor Covenant Code of Conduct.

[egolearner]

fix #2993

[egolearner]

@chenBright @wwbmmm please take a look

[wwbmmm]

Thank you for your contribution! I suggest to add a flag for backward compatibility: If the flag is on, add server tag for hash computing, if the flag is off, remain the original logic. Since consistent-hashing is always used in senarios that the servers are stateful, changing hashing logic may cause the request routed to new server that does not contain previous data for that request.

[egolearner]

Thank you for your contribution! I suggest to add a flag for backward compatibility: If the flag is on, add server tag for hash computing, if the flag is off, remain the original logic. Since consistent-hashing is always used in senarios that the servers are stateful, changing hashing logic may cause the request routed to new server that does not contain previous data for that request.

done

[egolearner]

@chenBright @wwbmmm please take a look， thx

[chenBright]

LGTM