allow erroring in navigateresult directly

[cheesycod]

Closes #581 which I made earlier for this. Adds a new NavigateError::Error variant to allow directly erroring luau require while in resolution process itself

[cheesycod]

OK, I am slightly unsure about this myself as rawlua init from ptr causes memory leaks on my mac requiring aggressive gc to clean up the mess rawlua leaves behind

@khvzak do you know any better api than rawlua::init_from_ptr since init from ptr causes hard to debug memory leaks right now that sometimes don’t even get resolved with gc when using it (this was actually the issue I had with mluas first require implementation before it switched to a luau function, init from ptr memory leaks like crazy)