translate images through translate instead of grid

[jo-mueller]

This PR uses thetranslate property to put images in a grid rather than the grid view. This makes the grid view nicer for napari>=0.6.2

cc #442

This pull request introduces enhancements to the bbbc_1_dataset function in the src/napari_clusters_plotter/_sample_data.py file, improving the organization of image data in a grid layout and adding new functionality for translating images and labels. Additionally, it includes a minor import update.

Enhancements to bbbc_1_dataset function:

• Added logic to compute the number of rows (n_rows) and columns (n_cols) for arranging images in a grid layout. This improves the visual organization of the dataset.
• Introduced translation calculations (translate_x and translate_y) to position images and labels within the grid, including a margin for spacing.
• Updated the layer tuples (ldtuple_image and ldtuple_labels) to include the translate property, ensuring proper placement in the grid.
• Removed viewer-specific grid settings (napari.current_viewer.grid.enabled and napari.current_viewer.grid.stride) to decouple the function from viewer-specific behavior.

Import update:

• Added numpy (np) import to support mathematical operations such as ceil for grid layout calculations.