Support Vue getters

[henribru]

Vue 3.3 introduced a concept of getters, similar to a computed except you don't actually wrap the function in a computed, making it simpler and also more performant in simple cases:

https://blog.vuejs.org/posts/vue-3-3#:~:text=%3C/script%3E-,Better%20Getter%20Support%20with%20toRef%20and%20toValue,-toRef%20has%20been

I think all that's really needed to support this in Tanstack Query is to use toValue instead of unref. The toValue implementation is very simple so I figure we can just copy it so we don't have to depend on Vue 3.3. Would such a contribution be welcome? The one downside I see is that if you have a function in your query key then this is actually a breaking change because it would be treated as a getter. Not sure if that's something people do 🤔

[DamianOsipiuk]

This seems to be interesting, but could be tricky to implement, due to the fact that we accept a set of functions in queryOptions, like queryFn, select etc and we do not actually want to evaluate them during unwrapping.
Additionally we need to deeply unwrap the options to account for nested refs.

[henribru]

You're right, it's definitely troublesome outside of the query key. I suppose it would be a bit too inconsistent to only apply it there. Oh well, I can live with some extra computeds