[2.x] Call toArray() on Arrayable props resolved from the Container

[pascalbaljet]

There's a bug in v2.0 in which Arrayable instances that are resolved from the container, for example with deferred props, are not correctly resolved because toArray() is never called on them. This PR fixes that and adds a test for it.

In the scenario below, both Users and Departments implement the Arrayable interface, but when resolving departments on a partial request, it currently returns an empty object.

return inertia('Users', [
    'users' => Users::make(),
    'departments' => Inertia::defer(fn () => Departments::make()),
]);