OpenSystemsDevelopment / qpdf

- Modify `traverseField` to return `bool` for identifying invalid fields.
- Add `bad_fields` set to track and handle problematic fields.
- Improve error handling for invalid parent entries.

- Add null pointer checks for schema objects.
- Refactor `checkSchemaInternal` for better readability and maintainability.
- Replace redundant error construction logic with lambda-based approach.
- Simplify array and dictionary schema handling.
- Remove unused test coverage statistics.

… for clarity and consistency across dictionary operations.

…up method implementations, and simplify member handling.

…ed_ptr and forward declaration.

…ng handling with `qpdf::String`, and clean up `Members` class implementation.

…` file and eliminate unneccessary creation of `Members` object.

…oved shared pointer handling, remove deprecated object methods, and update all references.

…sages, and clean up `QPDF.hh`.

… and `findEndstream` to `Objects`, remove `QPDF::PatternFinder` class, and update related logic for improved encapsulation.

…, replace direct calls with `QIntC` equivalents, and clean up `QPDF.hh`.

…t` consistency to handle invalid entries, and improve loop detection logic.

…` parameter, update conditional checks, and streamline logic for field and annotation handling.

Tighten validation of the PDF spec requirements that form fields form a tree and that widget annotations have a single parent by utilizing `field_to` and `annotation_to_field` in the loop detection check.

…with encapsulated `Config`, replace `qcf` with `d_cfg` for improved consistency, and adjust related logic for maintainability.

…`Lin`, encapsulate optimization data within `Lin`, update usage across the codebase, and streamline related logic in `QPDF_linearization`.

…` methods, update usage across codebase, and streamline related logic.

… `QPDFPageDocumentHelper`, consolidate redundant logic, and streamline method calls.

… streamline error handling, and improve encapsulation.

… and streamline stream handling.

…tion, and streamline stream registration logic.

…ta`and streamline foreign stream handling.

…prove encapsulation, and streamline stream data handling.

…eamline foreign object handling, and simplify method structure.

…object reservation, and streamline method usage.

…rect_object`, simplify object replacement, and streamline method usage.

…t usage of `std::shared_ptr`, simplify stream data management, and enforce `final` specifier.

Replace `getParsedOffset()` with the new `offset()` method across `QPDFObjectHandle` and related classes for consistent offset handling. Simplify logic and remove redundant `getParsedOffset()` implementation.

…proved encapsulation.

Encapsulate linearization-related logic in `QPDF::Doc::Linearization`. Refactor methods, relocate implementations, and update all references accordingly to streamline and centralize linearization functionality.

Relocate `Pages` methods to `QPDF::Doc` for improved encapsulation of page-related logic. Adjust all references and methods to use the new placement.

Refactor `pages` method and related members in `QPDF::Doc` to `page_dh`. Update all associated references to reflect the change.

Relocate `Objects` to `QPDF::Doc` for improved encapsulation of object-related logic. Adjust all relevant methods and references to use the new placement.