OpenSystemsDevelopment / qpdf

…ent and simplified temporary null management. Clean up unused test coverage markers.

Replace direct access to document helpers (`acroform()`, `pages()`, `embedded_files()`, etc.) with calls through `QPDF::doc()` for better encapsulation. Adjust related methods, constructors, and memory management accordingly.

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

- Added `validate()` invocation to `m->embedded_files`.
- Introduced `value_validator` to ensure only dictionaries are accepted in `EmbeddedFiles`.
- Enabled consistent value validation and key validation logic.

…rove memory management, and simplify initialization logic.

…cess for consistency and readability.

Using search and replace.

Remove any ambiguity around whether old or new value is being
returned.

Change .clang-format and commit automated changes from a fresh run of
format-code

Run this:

for i in  **/*.cc **/*.c **/*.h **/*.hh; do
  clang-format < $i >| $i.new && mv $i.new $i
done