Treat non scalar, non array, non RedirectResponse, non null as a Laravel compatible response
This brings AJAX handlers in line with page cycles, which do the same thing if the response is not a string. However in AJAX we should treat any scalar as a "result", not just a string. For all else (where not null), let Laravel handle it as a custom response object -- could be a model for serialization, or anything compatible.
Importantly to note when a custom redirect is sent, October's workflow is completely wiped out, so any partial updates, redirects, etc. will not occur. This is a normal and fair expectation.
Fixes#1784
7baea87068