optimize:enhance HttpClient to support h2c

[YvCeung]

• I have read the CONTRIBUTING.md guidelines.
• I have registered the PR changes.

Ⅰ. Describe what this PR did

优化并统一了 HTTP 客户端工具类，实现对 h2c 协议的兼容与支持。
1.Enhanced and unified the HTTP client utility to support the h2c protocol.

Ⅱ. Does this pull request fix one issue?

fix #7712
fix #7685

Ⅲ. Why don't you add test cases (unit test/integration test)?

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

the pr is one of the functions of another pr(#7736 ). After the merge, other parts of the #7736 will be submitted based on this

[codecov]

Codecov Report

❌ Patch coverage is 73.75000% with 21 lines in your changes missing coverage. Please review.
✅ Project coverage is 65.97%. Comparing base (c7e0ea7) to head (41973cd).
⚠️ Report is 2 commits behind head on 2.x.

Files with missing lines	Patch %	Lines
...a/org/apache/seata/common/util/HttpClientUtil.java	73.75%	14 Missing and 7 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##                2.x    #7740      +/-   ##
============================================
- Coverage     66.03%   65.97%   -0.06%     
+ Complexity      994      990       -4     
============================================
  Files          1324     1323       -1     
  Lines         50134    50137       +3     
  Branches       5921     5922       +1     
============================================
- Hits          33104    33077      -27     
- Misses        14129    14156      +27     
- Partials       2901     2904       +3     

Files with missing lines	Coverage Δ
...initializer/db/SqlServerResourceIdInitializer.java	78.57% <ø> (ø)
...a/org/apache/seata/common/util/HttpClientUtil.java	57.62% <73.75%> (+15.72%)	⬆️

... and 13 files with indirect coverage changes

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[funky-eyes]

LGTM