fix: HMR for query

[Rich-Harris]

At present, if you have something like this...

<script>
  import { foo } from './data.remote';
</script>

<p>{await foo()}</p>

...nothing immediately changes if you change the return value of foo — you have to reload the page to see the new data. This is unsatisfying.

With this PR, hot updates are accepted by the transformed remote module, and upon creating the replacement query we refresh anything that's currently referenced in an effect. The end result is HMR for queries.

Unfortunately this approach doesn't extend to prerender, because prerender functions don't use state and thus cannot be reactively updated. We could change that, but we would only want to change it in dev, and it would be a whole thing. Maybe we'll want to do that at some point anyway though.

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