Fix Qwen3-VL typos and clarify image/video/vision token descriptions

[stefgina]

What does this PR do?

hey, this PR fixes several small docstring issues in Qwen3-VL and adds a few clarifications:

• correction for the videos argument description ("image" → "video") in Qwen3VLProcessor.__call__().
• fixes various other typos in the processing & configuration files.
• the description was wrong for image_token_id, video_token_id, and vision_start/end_token_id
  so I updated it to distinguish modality tokens from the vision segment delimiters properly.

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• Did you write any new necessary tests?

Who can review?

@zucchini-nlp
@yonigozlan

[github-actions]

[For maintainers] Suggested jobs to run (before merge)

run-slow: qwen3_vl

[zucchini-nlp]

LGTM

[HuggingFaceDocBuilderDev]

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