feat: cluster information

[fengjiachun]

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What's changed and what's your intention?

Close #3294 , allow meta client to get some information of all nodes in the cluster, the implementation is divided into the following steps:

1. Two new heartbeat request handlers have been added: CollectDatanodeClusterInfoHandler and CollectFrontendClusterInfoHandler, which are used to process heartbeats requests from datanodes and frontends. These handlers extract information and write it into the in-memory KV storage on the metasrv leader node.
2. The cluster client access Metasrv's in-memory KV based on gRPC Service with read-only mode, offering range and batch_get APIs.
3. Implement the ClusterInfo trait for the cluster client, and implement the list_nodes method based on the kv service to return information about all node states.

Other: The information for the Metasrv node will not be included in this PR as it is about to exceed 1000 lines.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR does not require documentation updates.

[codecov]

Codecov Report

Attention: Patch coverage is 63.83442% with 166 lines in your changes are missing coverage. Please review.

Project coverage is 84.80%. Comparing base (097a037) to head (40f5dd2).
Report is 5 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3631      +/-   ##
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- Coverage   85.14%   84.80%   -0.35%     
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  Files         943      946       +3     
  Lines      157092   157547     +455     
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- Hits       133754   133604     -150     
- Misses      23338    23943     +605     

[fengjiachun]

The comments have all been resolved, please take a look @killme2008 @MichaelScofield

[killme2008]

LGTM