[CELEBORN-1317][FOLLOWUP] Improve parameters, description and document of REST API

[SteNicholas]

What changes were proposed in this pull request?

Improve parameters, description and document of Celeborn REST API, including:

1. The POST request uses @FormParam instead of @QueryParam.
2. The parameter name uses lowercase instead of uppercase.
3. The description of /exclude aligns with document in monitoring.md.
4. The document of REST API adds the Method and Parameters to document GET/POST method and corresponding interface.

Why are the changes needed?

The parameters, description and document of REST API need to improve after http server refine.

Does this PR introduce any user-facing change?

No.

How was this patch tested?

GA.

[SteNicholas]

Ping @turboFei, @RexXiong. PTAL.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 40.78%. Comparing base (121395f) to head (d66232e).
Report is 28 commits behind head on main.

❗ Current head d66232e differs from pull request most recent head ba0051b. Consider uploading reports for the commit ba0051b to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2495      +/-   ##
==========================================
+ Coverage   40.17%   40.78%   +0.61%     
==========================================
  Files         218      220       +2     
  Lines       13742    13962     +220     
  Branches     1214     1241      +27     
==========================================
+ Hits         5520     5693     +173     
- Misses       7905     7940      +35     
- Partials      317      329      +12     

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[RexXiong]

LGTM, thanks!

[RexXiong]

Merge to main(v0.5.0)