OpenSystemsDevelopment / qpdf

… and streamline stream handling.

… `StreamDataProvider` management.

Implement default constructor, copy/move constructors, and assignment operators for `Stream`. Add overloads for initializing `Stream` with `QPDFObjectHandle`.

Replace `getParsedOffset()` with the new `offset()` method across `QPDFObjectHandle` and related classes for consistent offset handling. Simplify logic and remove redundant `getParsedOffset()` implementation.

Relocate `Resolver` to `QPDF::Doc` for improved encapsulation of resolution logic. Adjust all references accordingly to use the new placement.

…ance error and warning handling within `BaseHandle` and `QPDF`, highlighting that the error condition is not covered in CI testing without generating codecov noise.

…y, and simplify implementation.

…erator[]`, and simplify null handling logic.

…actor implementation to simplify null handling and align with API conventions.

…ctionary key access, and simplify null handling logic.

- Added `Array::empty()` as a static method for creating empty arrays.
- Removed unused `Array(bool empty)` constructor and defaulted `Array` constructor.
- Updated `NNTree` methods to use `Array::empty()` for clarity and consistency.

… checking, and align with `Array` API conventions.

…prove bounds checking

…y, modify bounds checks, and adjust affected tests.

… to use subscript operators, and simplify object access logic.

…reamline object assignment, and introduce constructors for `QPDFObjectHandle`.

Refactor array handling in `QPDFObjectHandle`: replace `int` with `size_t` for size and index operations, introduce utility functions for type conversions, and simplify sparse array logic.

…string`, improving performance, simplifying stream data handling, and reducing dependency on `BufferInputSource`.

Replaced individual compression flags with a unified decode-level parameter for stream filtering. Introduced a helper function to handle filtering conditions, reducing redundancy and improving readability. Removed unused code and updated related tests to reflect these changes.

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.

Only top-level XMP metadata is supposed to be left unencrypted. All
other metadata is not treated specially.

... to QPDFObjectHandle_private.hh

- Add missing export for operator QPDFObjGen.

- Fix handling of indirect references. The use of the type_code method
  in various switch statements bypassed the special handling of
  ::ot_reference objects. Replace with new method resolved_type_code.

Add tests for ::ot_reference objects.

Move all stream-specific methods to new class qpdf::Stream

Move all array-specific methods to new class qpdf::Array.