Blazor movie tutorial QuickGrid styling

[guardrex]

Fixes #34218

• I'll place the new section at the end. That way, existing images don't require updates for taller rows.
• Going with five items per page.
• The sample apps were updated on Update movie dB tutorial sample apps blazor-samples#399.
• I'm making some improvements to what we placed on the earlier PR in the QuickGrid article. I think we should show the QG wrapped. I'd like to head off any possibility of issues being opened on that point, which is buried in the text of our earlier PR. However, I do use a much shorter QG example (diff) to demo it. Also, I'm splitting that out into its own section and making it clear that you're styling all rows with the approach that happens to include empty rows.

❓ Do you want to further scope the styles to the QG using its Class property?

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Internal previews

📄 File	🔗 Preview link
aspnetcore/blazor/components/quickgrid.md	aspnetcore/blazor/components/quickgrid
aspnetcore/blazor/tutorials/movie-database-app/part-8.md	aspnetcore/blazor/tutorials/movie-database-app/part-8

[danroth27]

LGTM