#23021 feat(python): expose all config properties in constructor

Configuration options that were only assignable after construction are now constructor parameters for the Python generator, so callers can set them in one place.

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  ./mvnw clean package || exit
  ./bin/generate-samples.sh ./bin/configs/*.yaml || exit
  ./bin/utils/export_docs_generators.sh || exit
  

  (For Windows users, please run the script in WSL)
  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
  IMPORTANT: Do NOT purge/delete any folders/files (e.g. tests) when regenerating the samples as manually written tests may be removed.
• File the PR against the correct branch: master (upcoming 7.x.0 minor release - breaking changes with fallbacks), 8.0.x (breaking changes without fallbacks)
• If your PR solves a reported issue, reference it using GitHub's linking syntax (e.g., having "fixes #123" present in the PR description)
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

cc @cbornet (2017/09) @tomplus (2018/10) @krjakbrjak (2023/02) @fa0311 (2023/10) @multani (2023/10)

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Summary by cubic

Expose all Python client Configuration options as constructor parameters so users can set everything at initialization. Defaults are preserved; samples and docstrings updated, and pydantic v1 templates remain unchanged after reverting earlier additions.

• New Features
  • Added constructor args for verify_ssl, assert_hostname, tls_server_name, connection_pool_maxsize, proxy, proxy_headers, safe_chars_for_path_param, client_side_validation, socket_options, datetime_format, and date_format.
  • Connection pool size is configurable; passing None keeps defaults (100 for async, cpu_count*5 for sync).
  • Regenerated samples to reflect the new constructor options.