[BUG][PYTHON] Fix #23990: Account for content-type parameters on request preparation

[MarcelKonrad]

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Fixes #23990. A description and a guide on how to reproduce the issue can be found there.

The proposed changes include a new helper function called contenttype_matches that returns true when a given content-type string matches the given type and subtype, otherwise it returns false. Mime type parameters are ignored, but can be optionally be present in the provided string. It also allows for vendor specifications. For example, application/vendor+json is also considered valid against type=application, subtype=json.

@cbornet @tomplus @krjakbrjak @fa0311 @multani

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Summary by cubic

Fixes #23990 by making the Python client’s content-type matching ignore parameters (including optional whitespace) and accept vendor suffixes so request bodies use the correct encoder.

• Bug Fixes
  • Added contenttype_matches helper (case-insensitive, ignores MIME parameters/whitespace, supports +vendor suffix).
  • Switched JSON, application/x-www-form-urlencoded, and multipart/form-data detection to use the helper.
  • Moved the helper to module scope and updated templates/samples; also use content_type for text/* boolean handling.

^{Written for commit f34fbbf. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 1 file

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[cubic-dev-ai]

2 issues found across 5 files (changes from recent commits).

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[MarcelKonrad]

The pipeline failed because it could not pull the specified docker image due to a connection timeout, which is unrelated to this PR.