Chore: fixed console warnings of prop types

[stackoverfloweth]

from a typescript perspective modalValue: T | null | undefined === modalValue?: T | null
vue's defineProp perspective must be different, because the former results in a bunch of console warnings

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[pleek91]

I actually don't think we should change this. The two are not equal even in typescripts eyes. { foo?: string | null } is different than {foo: string | null | undefined} in the fact that a non optional prop must be passed. TS Playground example. Changing this means our component types will not require the modalValue be passed and our components don't work without that prop. Which I believe would cause errors at runtime. Which is a poor developer experience.

Also, I believe a fix for this will be coming in the not to distant future.
Issue
PR

For now I'd rather deal with the warnings OR at an implementation level coaless undefined to null