feat: Add parallelized health check mechanism for Raft nodes

[SAIVARDHAN15]

• I have registered the PR changes.

Ⅰ. Describe what this PR did

• Implemented a isNodeAlive method to check the health of each node via HTTP requests.
• Added performHealthCheck method to perform parallel health checks on a list of nodes using Java Streams.
• Integrated the health check into the refreshAliveLookup method for Raft mode.
• Optimized the process by filtering out the leader node from the alive nodes list.
• Improved node reliability by ensuring unresponsive or down nodes are detected and filtered efficiently.

Ⅱ. Does this pull request fix one issue?

This PR adds a new health check feature for Raft nodes but does not fix any pre-existing issues.

Ⅳ. Describe how to verify it

Deploy a Raft cluster with Seata.
Simulate node failures or unresponsive states.
Trigger refreshAliveLookup and confirm unhealthy nodes are excluded.
Check logs for correct identification of down nodes.
Ensure leader node is retained if healthy.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 14 lines in your changes missing coverage. Please review.

Project coverage is 51.77%. Comparing base (66bd3a4) to head (c28c6b5).

Files with missing lines	Patch %	Lines
...scovery/registry/raft/RaftRegistryServiceImpl.java	0.00%	14 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x    #6920      +/-   ##
============================================
- Coverage     52.52%   51.77%   -0.76%     
+ Complexity     6542     6459      -83     
============================================
  Files          1122     1122              
  Lines         39857    39867      +10     
  Branches       4668     4670       +2     
============================================
- Hits          20936    20641     -295     
- Misses        16925    17264     +339     
+ Partials       1996     1962      -34     

Files with missing lines	Coverage Δ
...scovery/registry/raft/RaftRegistryServiceImpl.java	16.94% <0.00%> (-0.75%)	⬇️

... and 31 files with indirect coverage changes

[funky-eyes]

Hi @SAIVARDHAN15 , when refreshAliveLookup is called, it has already undergone a health check by NettyClientChannelManager#doReconnect. I tested it locally and confirmed that the health check is normal, so this task might be a misunderstanding? Due to the issues from #6919 and #6917, I have been mistakenly thinking that the health check was failing. If you're interested, you can take on these two tasks.