Samples: Add GPU/CUDA samples and update for SDK 2.18.0

[csu-bot-zivid]

Updates the Python samples for Zivid SDK 2.18.0, headlined by a new
set of GPU/CUDA samples plus several new and improved samples.

New GPU samples (source/applications/advanced/cuda)

• capture_and_process_image_with_cupy_on_cuda — wrap a Zivid GPU
  image buffer as a CuPy array without copying it through CPU memory.
• capture_and_render_point_cloud_with_opengl_on_cuda — capture a
  point cloud and render it interactively using CUDA-OpenGL interop,
  copying device-to-device without a CPU round-trip.
• capture_and_segment_image_with_pytorch_on_cuda — pass a Zivid
  GPU image into a PyTorch/torchvision segmentation model zero-copy.

Other new samples

• mask_point_cloud — read a point cloud from a ZDF file, apply a
  binary mask, and visualize it.
• connect — connect to a camera by first available, serial
  number, IP address, or hostname.
• create_file_camera_from_zdf_with_diagnostics — capture a frame
  with diagnostics and create a file camera from it.
• check_health — poll the camera health check from a separate
  thread while capturing in the main thread.

Updated samples

• barcode_detector — separate linear-barcode detection from
  decoding, report bounding boxes, and add the ITF format.
• capture_with_settings_from_yml — save and load a 2D frame and
  read a ZDF file's frame type.
• capture_with_diagnostics — additionally capture and save a 2D
  diagnostics frame.
• camera_info — print individual camera temperatures.
• roi_box_via_aruco_marker / roi_box_via_checkerboard — use
  the region-of-interest mask API and a ZDF file camera.
• stitch_using_robot_mounted_camera — crop each viewpoint with a
  workspace ROI box defined in the robot base frame.
• capture_from_file_camera and file-camera visualization — load
  file cameras from ZDF files with diagnostics.
• automatic_network_configuration_for_cameras — report host- and
  camera-side Ethernet link speed.

Fixes and docs

• README now lists the new samples and a GPU Access tutorial.
• Type annotations and lint tidy-ups across the GUI helper modules,
  plus a few docstring corrections.
• Samples and CI updated for Zivid SDK 2.18.0.