OpenSystemsDevelopment / qpdf

…std::string_view`, improving performance and code clarity.

…ancy and improving initialization consistency.

…ndant methods for improved code clarity.

…ng encapsulation and maintainability.

Replaced raw key pointer and length parameters with a `std::string` in `Pl_AES_PDF` and `Pl_RC4` constructors for improved safety and clarity. Updated all usage sites accordingly, reducing reliance on manual memory management and redundant conversions.

…proved clarity and reduced indirection in pipeline management.

…proved clarity and reduced indirection in pipeline management.

…buffer handling and streamline compression.

…n and improve separation of concerns.

…pping, remove redundant `PipelinePopper` usage, and improve encapsulation of MD5 handling.

# Conflicts:
#	libqpdf/QPDFWriter.cc

…implifying ID management and ensuring consistent initialization.

…y management and eliminate redundant `dynamic_cast` logic.

…, improving encapsulation and memory management. Remove the now redundant `pushMD5Pipeline` method and streamline MD5 activation.

…line `linearization pass1` logic  when writing pass1 file

…te encryption handling

…mplified pipeline stack management in `QPDFWriter`.

…ify pipeline stack management

Encapsulated pipeline stack management into a dedicated `Pl_stack` class within `QPDFWriter::Members`. Reorganized related methods to streamline and simplify initialization and activation of pipelines, removing redundant code.

…dundant normalization and string unparse logic across multiple write calls.

…ndling, leverage `std::string_view`, and streamline QDF indent logic.

… overloads, streamline QDF handling, and simplify string and trailer writes.

…onsolidate `iterate_rc4` logic, and streamline RC4 key processing.

…arrays with `std::string`, and simplify key computation logic.

…ect `substr` calls, and simplify password handling logic.

…ys with `std::string`, and simplify related password handling logic.

…implify padding logic, and streamline password handling across methods.

…nline previously separate method, and streamline data encoding logic.

…ased logic in `setEncryptionMinimumVersion`, and reduce redundancy across `QPDFWriter` methods.

…ption dictionary generation, and reduce redundancy in encryption handling logic.

… encryption handling, and reduce redundancy across methods.

…`, simplify method signatures, and centralize logic in `QPDF::EncryptionData` for improved maintainability.

…ng in method parameters, and simplify encryption logic for improved maintainability and reduced redundancy.

…uce redundancy, improve maintainability, and streamline parameter handling.

…ling, and improve maintainability.

…Perms_value_V5` methods; inline their logic into `setV5EncryptionParameters` to simplify encryption data processing.

…dom_string`, improve readability of salts and keys handling, and streamline `compute_Perms_value_V5_clear` logic by returning strings directly.

…std::bitset`, reorganizing related methods, and simplifying access to improve clarity and maintainability.