OpenSystemsDevelopment / qpdf

Recognise that JSON objects are effectively shared pointers to JSON_value.

Refactor creation of object descriptions

Eliminate the use of shared pointers in JSONParser

Allow access to private header files when defining data members.

Use string_view parameters and call pipeline write methods directly.

Also, make QPDFObjectHandle(std::shared_ptr<QPDFObject> const&) public.

A new private overload of QPDF::makeIndirectObject breaks pikepdf's
build, so renaming function.

…ternal2 and copyObject2