Type guards for response types

[swantzter]

The lvs-types library is quite nice, and the zod schemas for request body validation is a great touch. However, it'd be nice to get a similar level of type safety for API responses using type guard functions

For example, instead of doing something like const body = await response.json() as ISeasonV1 I prefer doing something like the following to be sure I have a valid response and at least the fields that are interesting in my implementation:

function isISeasonV1 (x: unknown): x is ISeasonV1 {
  return isObject(x) && typeof x.inviteURL === 'string' // ...
}

const response = await fetch(...)

if (!response.ok) { ... }

const body = await response.json()

if (!isISeasonV1(body) {
  throw new TypeError('AAAAA, WE GOT BAD DATA FROM THE API AND NOW EVERYTHING IS ON FIRE. SAVE YOURSELF WHILE YOU STILL CAN!!!!!!!')
}

// continue processing the response

It'd be a nice addition imo to both get type safe input and output