Add copy and move semantics to RaycastingScene

[michal-bakshi]

Type

• Bug fix (non-breaking change which fixes an issue): Fixes #
• [ x ] New feature (non-breaking change which adds functionality). Resolves Make it possible to copy a RaycastingScene #7014
• Breaking change (fix or feature that would cause existing functionality to not work as expected) Resolves #

Motivation and Context

Checklist:

• [ x ] I have run python util/check_style.py --apply to apply Open3D code style
  to my code.
• [ x ] This PR changes Open3D behavior or adds new functionality.
  • [ x ] Both C++ (Doxygen) and Python (Sphinx / Google style) documentation is
    updated accordingly.
  • [ x ] I have added or updated C++ and / or Python unit tests OR included test
    results (e.g. screenshots or numbers) here.
• [ x ] I will follow up and update the code if CI fails.
• [ x ] For fork PRs, I have selected Allow edits from maintainers.

Description

Implemented the copy constructor, copy assignment operator, move constructor, and move assignment operator in C++. Exposed these methods via pybind11 to support copy.deepcopy() in Python. Added comprehensive unit tests in test_raycasting_scene.py covering copy/move scenarios.

[update-docs]

Thanks for submitting this pull request! The maintainers of this repository would appreciate if you could update the CHANGELOG.md based on your changes.