Add a class that directly wraps a C++ sequence container, allow for modifying them. For all instantiated containers, generate a special (sequence) type that wraps the C++ container directly. For example, it will be accessible as a QList_int. This is achieved via providing a template for a type private that relies on a conversion traits template for conversion. Only the conversion traits specialization code needs to be generated. Use cases: - Allowing for modifying Fields of such container types (non-owning) - Pass it into functions taking such containers instead of converting back and forth from a PyList (constructed in Python, owning) [ChangeLog][shiboken6] Support for opaque C++ sequence scontainers has been added, allowing to pass a wrapped C++ container directly instead of converting it back and forth from Python sequences. Task-number: PYSIDE-1605 Change-Id: I49d378eb1a0151730d817d5bdd4b71a7c3b5cdda Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org> Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>