OpenSystemsDevelopment / qpdf

…and replace it with a setter that directly sets `Input::password`, centralize password handling, simplify file processing, and adjust related logic in `handlePageSpecs`.

…input_entry`, centralize input file handling in `infile_name`, update `new_selection` logic, and simplify page range and input processing.

…gic in `handlePageSpecs` and `new_selection`, and simplify page processing.

…alize handling in `Files::process_all`, and simplify `handlePageSpecs`.

…file handling in `Inputs`, and simplify related logic.

…lePageSpecs` and `new_selection`, and simplify page specification handling.

…, replace redundant file warning logic in `handlePageSpecs`, and simplify resource management.

…zation, simplify `handlePageSpecs` and `new_section`, and streamline file processing logic.

…ce removal handling, and cleanup redundant code in `handlePageSpecs`.

…sing, and simplify page specification handling.

…date page handling logic in `Input`, and optimize page range processing.

…ing logic, and streamline password handling and verbose output.

…ine file handling and resource management logic.

…page_heap` and `page_spec_qpdfs`, simplify file handling, and improve code clarity.

…ange handling, and cleanup obsolete logic.

…n` method, and update logic for handling page specifications.

…ageDocumentHelper` dependency, simplifying page and form field operations, and updating test coverage.

…parameter, return success status, and streamline warning handling logic.

…based structure for page mapping, improve indexing logic, and clean up redundant variables.

…mline numeric range parsing, and clean up obsolete test coverage entries.

…minate redundant variables, and simplify underlay/overlay page handling logic.

…ges, replace redundant variables, and improve code readability.

…e number and index handling, update related logic accordingly.

…ors for `Members` and `ProgressReporter`

…DFJob_private.hh`, streamline includes, and reduce header dependencies.

… shared helper retrieval, validation methods, and update usages across the codebase. Remove unused test coverage entries.

…t. Add shared helper retrieval, validation methods, and update usages across the codebase.

…le handling. Add shared helper retrieval, validation methods, and update usages across the codebase.

Integrate `QPDFPageLabelDocumentHelper` with `QPDF` for improved page label handling. Add methods for retrieving shared helper instances, validating page label structures, and streamline usage throughout the codebase.

…n `QPDFWriter` and `QPDFJob`.

…()` method, remove redundant helper functions, and streamline related logic for consistency and maintainability.

…ated `acroform()` method and update related references for improved performance, consistency and maintainability.

…mplify array traversal, and centralize `empty` checks for improved clarity and efficiency.

… pipelines and simplify conditions.

Introduce null checks for `callbacks` in `QPDFObjectHandle` to allow content streams to be parsed without ParserCallbacks. Update `QPDFJob` to pass `nullptr` instead of `DiscardContents` for parsing.

Replaced std::shared_ptr<char> with std::string for passwords in QPDFJob. This simplifies memory management and aligns the implementation with modern C++ standards, improving code readability and maintainability.

Replaced shared pointer usage with a plain std::string for passwords in PageSpec to simplify code and enhance readability. Updated relevant logic and function calls to align with this change, removing unnecessary shared pointer management. Updated TODO to reflect completion of this modernization step.