Feature Request: Support both width and height in Blazor Virtualize

### Is your feature request related to a problem? Please describe.
I am trying to display several thousand image thumbnails in a grid layout with Blazor and virtualize scrolling through the thumbnail gallery to improve performance.

### Describe the solution you'd like
The ability to set both the known width and height of the elements within a `` component in Blazor, and have the virtualization take into account multiple items per "row", whether the number of items per "row" is dynamic based on the available width of the container and the provided `ItemWidth`. Something like this:
```

### Additional context
Apologies if this is somehow already possible and a couple of hours of Googling hasn't led me to the answer - I'm new to Blazor.