DRAFT: Update library to incorporate recent SvelteKit breaking changes

[MrTact]

Fixes MacFJA/svelte-outh2:#1

[ctrlsam]

@MacFJA would you be able to review this?

[bgronek]

@MacFJA Any updates here? This looks like a great project with a lot of future potential. Do you need co-maintainers?

[bgronek]

@MrTact Based on @MacFJA 's activity on the base project (nothing in over a year and it's not pinned to his profile), perhaps it might make sense for you to publish your fork to npm? This is a great project with a lot of future potential and it would be a shame to see it die on the vine.

[MacFJA]

SvelteKit has just being release into version 1.0.0

I will probably do a complete rework of this lib 🤔

---

I can merge the work done here (most of it seem good, I didn't review it completely)

---

And for the pin repositories, GitHub only allow 6 pin repositories, I have more than 40 repositories, I can't make them all pinned 😅 .
But it's true that lately this repository has a bit less love than other ones