feat: enable sugar ref take 2 for vue3-jest

[cexbrayat]

This PR allows testing components using sugar ref take 2 vuejs/rfcs#369

Note that I did not make it configurable for now, but maybe it should be. Opinions?

[lmiller1990]

Nice. What do you mean by configurable? If you aren't using the ref sugar, you won't be impacted by this update, right?

[cexbrayat]

I think you won't be impacted (we could merge and release an alpha to make sure of it on our projects).

The probable edge case is someone naming its own variables $ref or another reserved sugar syntax... In that case, vue-jest will transform them and probably error, whereas vue-next will not unless explicitly told? I'm not 100% sure, as I'm not using sugar ref in my own projects.

[lmiller1990]

It seems really unlikely someone named their variable $ref, so I think this is fine.

[sibbng]

Ref take 2 also includes helpers like $() and $$() which can be conflict with https://github.com/antfu/v-dollar or any function named as or aliased to $ like:

import { unref as $ } from 'vue'

I don't think people do that more often than using new ref syntax with script setup, but it would be weird to make people disable new ref transform on jest config whilst they didn't enable it on their app.