fix: remote forms with default values defined by field.as('text', defaultValue) now correctly reset to the provided default values once submitted

[ottomated]

Without JS enabled, a form like this:

<form {...my_form}>
  <input {...my_form.fields.foo.as('text', 'default')} />
  <button>Submit</button>
</form> 

will reset the text field to "default" when submitted. With progressive enhancement, when form.reset() is called on submission by SvelteKit, the text field is incorrectly reset to "".

This PR fixes that by adding defaultValue and defaultChecked to the object returned from .as(). It seems like the behavior for <select> elements was already correct?

Depends on #15752 for correct checkbox behavior.

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Latest commit: 34ef4dd

The changes in this PR will be included in the next version bump.

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Preview: https://svelte-dev-git-preview-kit-15753-svelte.vercel.app/