fix: update TypeScript types

[G-Rath]

This overhauls the types so that they actually work for Vue 3, being primarily based on the prop types for each component/mixin and tested locally using a project of mine.

They're by no means perfect but they'll mean type checking actually works properly and they can be refined over time - unfortunately I'm not sure if it'll be possible to strictly type everything due to the large degree of freedom around handling object-type options (i.e. trackBy and label, which in theory should be supportable with generics, except with the way Vue types work I'm not sure it'll be possible to actually properly pass generics around), but this should at least get the ball rolling.

As I've only just started exploring this library, I'm happy to be told if a prop should be of a particular type.

[mattelen]

@akki-jat as the TS pro, would you like to review this one?

[akki-jat]

@akki-jat as the TS pro, would you like to review this one?

Sure @mattelen. I will check.

[akki-jat]

@G-Rath Please re-base your branch with latest master

[G-Rath]

@akki-jat there you go

[akki-jat]

Awesome work @G-Rath 👏

[ghrapan]

Great work! But I'm afraid there is an error in the types - the modelValue can also be null (a null is both accepted and returned if nothing is selected - check update:modelValue events in the code).

BTW, returning null instead of undefined is a major drawback of this otherwise great library. I have to use it with a wrapper that converts null to undefined.

[G-Rath]

@ghrapan feel free to do a pull request to refine the types further!

[ghrapan]

@akki-jat Please review the #1853