OpenSystemsDevelopment / qpdf

qpdf permits replacing standard stream filters with user provided filters.
#1457 incorrectly removed that option.

Removed `expand_filter_name` method and integrated its functionality directly into `filter_factory` for improved clarity and maintainability. Consolidated filter handling logic to eliminate redundant operations and streamline code execution.

Moved stream filter factory logic into `Members::filter_factory` for better encapsulation and maintainability. Removed redundant static filter factory map and improved error handling for invalid stream filter configurations.

Moved the filter abbreviation expansion logic from a static map to a new `expand_filter_name` method in `QPDF_Stream::Members`. This simplifies the code, improves maintainability, and consolidates the logic for easier testing and updates.

Only build strings when needed.

... to QPDFObjectHandle_private.hh

Except for virtual functions to avoid the need for users to update code.

This reverts commit ff2a78f579ebdd06b417e34260a17dba06e71137, reversing
changes made to 8f54319f7a6514110f4b05cbbf1cb1c9fc8cb6a0.

Create an alternative to getJSON to allow an object handle to be written as JSON without the overhead of creating a JSON object.

Also, name the type QPDFValue::Description.

Remove parameters and return the description.

Set parsed offset at the same time as setting description.

Avoid dynamic casting.

Add optional parameter shallow. Change logic errors to runtime errors.

QPDFValueProxy wasn't a good name for it. We decided the evil of
having the header file be named QPDFObject_private.hh was less than
the evil of having the class be named something other than what it
should have been named.

Preparing to change the class name back to QPDFObject