[SPARKNLP-1318] Reader2Image Integration with AutoGGUFVisionModel

[danilojsl]

Description

This PR extends Reader2Image to support interoperability with AutoGGUFVisionModel by introducing flexible handling of encoded vs. decoded image bytes and optional prompt output.

Key changes

• Added a new parameter useEncodedImageBytes to control whether the image result stores:

  • Encoded (compressed) file bytes for models like AutoGGUFVisionModel
  • Decoded pixel matrix for models such as Qwen2VLTransformer

• Implemented outputPromptColumn parameter to optionally output a separate prompt column containing text prompts as Spark NLP Annotations.

Motivation and Context

Complete integration of Reader2Image with VLM models

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Code improvements with no or little impact
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING page.
• I have added tests to cover my changes.
• All new and existing tests passed.