fix(pypdfium2): Fix OCR bounding box misalignment caused by mismatched rotation metadata

[AndrewTsai0406]

I fixed the OCR bounding box misalignment issue by reading the rotation metadata from scanned PDF pages and applying the necessary adjustments in the pypdfium2 backend. This ensures that bounding boxes align correctly with the visually rotated pages during OCR detection.

Issue resolved by this Pull Request:
Resolves #2038

Checklist:

• Documentation has been updated, if necessary.
• Examples have been added, if necessary.
• Tests have been added, if necessary.

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Codecov Report

❌ Patch coverage is 0% with 7 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
docling/backend/pypdfium2_backend.py	0.00%	7 Missing ⚠️

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[AndrewTsai0406]

Added a test case that looks for word that doesn't exist in result from orginal pypdfium2 backend ocr pipeline

[AndrewTsai0406]

The result of ocr is usually not deterministic, can anyone help me with testing please.😢

doc_pred = DoclingDocument(schema_name='DoclingDocument', version='1.5.0', name='ocr_test_rotation_mismatch', origin=DocumentOrig...], key_value_items=[], form_items=[], pages={1: PageItem(size=Size(width=595.0, height=842.0), image=None, page_no=1)})
doc_true = DoclingDocument(schema_name='DoclingDocument', version='1.5.0', name='ocr_test_rotation_mismatch', origin=DocumentOrig...], key_value_items=[], form_items=[], pages={1: PageItem(size=Size(width=595.0, height=842.0), image=None, page_no=1)})
fuzzy = True

    def verify_docitems(doc_pred: DoclingDocument, doc_true: DoclingDocument, fuzzy: bool):
>       assert len(doc_pred.texts) == len(doc_true.texts), "Text lengths do not match."
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
E       AssertionError: Text lengths do not match.

tests/verify_utils.py:231: AssertionError