[Feature]: Treat null as an empty value for Select

[kilobyte2007]

Describe the feature

From what I see here, for the Select component - only undefined and '' is treated as an empty value - see here: https://github.com/radix-vue/radix-vue/blob/main/packages/radix-vue/src/Select/utils.ts

Is there any reason why null is not treated the same way? If it's a design decision - I think it would make sense to have a way to configure this somehow.

The same situation is present in ToggleGroup, Calendar, and some other components where null is not accepted as a type while it's a pretty common situation where some values can come as null from a backend or API.

Additional information

• I intend to submit a PR for this feature.
• I have already implemented and/or tested this feature.

[zernonia]

Thanks for the issue @kilobyte2007 .. I think it make sense to consider null as nullish value and show the placeholder here