Fix HTTPConnection.communicate() to pass server proxy and strict mode settings

[andrewkernel]

❓ What kind of change does this PR introduce?

• 🐞 bug fix
• 🐣 feature
• 📋 docs update
• 📋 tests/coverage improvement
• 📋 refactoring
• 💥 other

📋 What is the related issue number (starting with #)

Resolves #823.

❓ What is the current behavior? (You can also link to an open issue here)

HTTPConnection.communicate() initialized request handlers with default proxy_mode and strict_mode values instead of the server's configured values.

❓ What is the new behavior (if this is a feature change)?

HTTPConnection.communicate() now passes proxy_mode=self.server.proxy_mode and strict_mode=self.server.strict_mode when constructing the request handler.

📋 Other information:

Added docs/changelog-fragments.d/831.bugfix.rst.

Testing:

• .venv\Scripts\python.exe -m pytest --no-cov -n 0 cheroot/test/test_server.py -k communicate_uses_server_proxy_and_strict_mode

📋 Contribution checklist:

• I wrote descriptive pull request text above
• I think the code is well written
• I wrote good commit messages
• I have squashed related commits together after the changes have been approved
• Unit tests for the changes exist
• Integration tests for the changes exist (if applicable)
• I used the same coding conventions as the rest of the project
• The new code doesn't generate linter offenses
• Documentation reflects the changes
• The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences

[read-the-docs-community]

Documentation build overview

📚 cheroot | 🛠️ Build #33486629 | 📁 Comparing d258498 against latest (3937fe1)

  🔍 Preview build  

6 files changed · ± 6 modified

± Modified

• genindex/index.html
• history/index.html
• pkg/cheroot/index.html
• pkg/cheroot.server/index.html
• pkg/cheroot.test/index.html
• pkg/cheroot.test.test_server/index.html

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 54.74%. Comparing base (3937fe1) to head (d258498).

Additional details and impacted files

@@             Coverage Diff             @@
##             main     #831       +/-   ##
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- Coverage   78.19%   54.74%   -23.46%     
===========================================
  Files          41       12       -29     
  Lines        4788      411     -4377     
  Branches      547        1      -546     
===========================================
- Hits         3744      225     -3519     
+ Misses        905      186      -719     
+ Partials      139        0      -139     

[julianz-]

This PR addresses an inconsistency in _serve_unservicable but the real issue from #823 is in communicate() at line 1309, where RequestHandlerClass is always initialized with default proxy_mode and strict_mode. The fix should be to pass proxy_mode=self.server.proxy_mode, strict_mode=self.server.strict_mode there instead.

[julianz-]

I updated the title of this PR as your original one no longer applied. You need to update your commit message similarly and also ensure the body is line-wrapped at ~72 characters - there is a linter error about this currently.