File loading is not VS Code Remote compliant

[PEZ]

In #38 it is brought up that when loading files we read them us the node fs module, which we can't do if Joyride should work in remote scenarios (which are plenty and very common).

Here's where it happens: https://github.com/BetterThanTomorrow/joyride/blob/217e81c589708253382c9f4b81363bed4bb8b27c/src/main/joyride/sci.cljs#L38

[borkdude]

If we need to load files asynchronously, then we need to rewrite to the SCI async API, which is not yet finished. So I think I'll take this as an opportunity to improve that while working on this if you don't mind.

[PEZ]

Sounds excellent! Will that bring us closer to nbb-style top-level await?

[borkdude]

Yes