fix!: handle non-inertia location redirects

[innocenzi]

Sometimes, we want to perform an external redirect that can be initiated on the first visit or on an Inertia visit.

In such a case, Inertia's location won't work because it will only simply return a normal 409 response with the X-Inertia-Location, but since the front-end is not loaded the end result will be a blank page.

To fix this, we need to check if the current request is an Inertia one, perform the location redirect, or return a classic RedirectResponse otherwise.

This PR fixes that issue by performing that check internally so the developer doesn't have to.

This is technically a breaking change since I had to modify the original test, but it's a breaking change that is more likely to fix issues than to create some.

---

TL;DR: with this PR, instead of doing:

if (request()->inertia()) {
    return inertia()->location($url);
}

return redirect()->to($url);

We can just do:

return inertia()->location($url);

---

Fixes #295

[narasimhajupally]

Hello, I just checked the code changes for this issue and tried to do similar in my controller

if (Request::inertia()) {
       return Inertia::location(tenantRoute($email->domain->domain, 'home'));
}
return redirect(tenantRoute($email->domain->domain, 'home'));

I am getting this exception
ErrorException Cannot unbind $this of closure using $this
any idea ?
Thanks.

[claudiodekker]

Thanks @innocenzi!