[Tests] Amend typos and <Set /> typings

[Philzen]

Just a handful of test name and typescript amendments – discovered while skimming over https://github.com/redwoodjs/redwood/pull/10464/files

[Philzen]

@Tobbe i'm afraid you're not going to like this (packages/router/src/tests/router.test.tsx):

#11739 was still fine – it's also what i would love to see in the next v8 patch release as it fixes what broke during the migration from 7 → 8.

Starting with #11756 the typing all went downhill 🙈
Issue there

• It was in theory a nice idea of me to use keyof AvailableRoutes for autocompletion, but poorly executed as of course it only worked with my locally generated types in the .redwood folder. So any route name occurences would either have to be @ts-ignored ignored now in the main project or we'd need to find another way to generate those route typings.
• Then this change (i believe) then broke the nested types

Not sure if this is easily fixable or if we maybe should revert starting from #11756 for the time being and try another day. Just wanted to quickly share this as a heads up.