Request: Add ShouldRevalidateArgs to generated Route namespace

[ngbrown]

When importing generated types for a route, import type { Route } from "./+types/route";, there is no analog to ShouldRevalidateFunctionArgs in Route.

Because there are two sets of route params, currentParams and nextParams in ShouldRevalidateFunctionArgs it seems like an good candidate type to generate.

So that's what this request is, to add the Route.ShouldRevalidateArgs and Route.ShouldRevalidateFunction types to the generated code when react-router typegen is ran.