Creating templated links when pointing to controller methods in Kotlin

Currently, if we want a templated URI that we do not manually build ourselves, we can do
linkTo(methodOn(UserController::class.java).getUser(null)).withRel("user")

This works fine with Java as we can pass null parameters to any method, but it does not work well in Kotlin, as in Kotlin we have to explicitly make our method's parameters nullable. This creates opportunities for mistakes and undermines the inherent safety of kotlin, making us do null checks just like in java instead of being able to assure that this controller method can not accept nullable parameters.

It would be nice if we had some other way to do this that isnt building the URI manually.

Start by reviewing the linkTo(methodOn(...)) usage described in the issue and how templated controller-method links are currently created. Define an alternative that avoids nullable Kotlin controller parameters while preserving templated URI generation; done means Kotlin callers can keep non-null parameter types without manually building the URI.