Prepare for deprecation of ViewAllocateWithoutInitializing

[dalg24]

Per comment in the code, ViewAllocateWithoutInitializing was there only for backward compatibility. Moving away from it allows us to get rid of two View constructor overloads*.
Admittedly the changes I propose would break code that relied on Kokkos::ViewAllocateWithoutInitializing being an actual type but I think it is ok.

I considered adding an implicit conversion from ViewAllocateWithoutInitializing to Impl::ViewCtorProp<std::string,Impl::WithoutInitializing_t> because that solution would be safer for code downstream. In fact, it was originally my plan but it turned out to be harder than I thought. I managed to implement it with the help from @nliber but it forced me to change all the overloads that took Impl::ViewCtorProp<P...> and I ended dropping the idea because the complexity added was not worth it.

You will notice I haven't actually yet deprecated the use of ViewAllocateWithoutInitializing. My intent is to make sure we remove it from all examples and tutorials and perform the deprecation later. Hopefully by then we will be able to use the deprecated attribute from C++14.

TLDR Make ViewAllocateWithoutInitializing a function that generates a Impl::ViewCtorProp rather a concrete type an alias in preparation for deprecation/removal.

*Don't worry we still have 14 besides besides the special members!

[dalg24]

I had a peek at Trilinos and this PR would break

packages/muelu/test/scaling/MMKernelDriver.cpp:282:    using no_init_view=Kokkos::ViewAllocateWithoutInitializing;
packages/muelu/test/scaling/MMKernelDriver.cpp:442:    using no_init_view=Kokkos::ViewAllocateWithoutInitializing;
packages/muelu/test/scaling/MMKernelDriver.cpp:689:        using no_init_view=Kokkos::ViewAllocateWithoutInitializing;
packages/muelu/test/scaling/MMKernelDriver.cpp:842:    using no_init_view=Kokkos::ViewAllocateWithoutInitializing;
packages/shylu/shylu_node/tacho/src/impl/Tacho_Util.hpp:531:  using do_not_initialize_tag = Kokkos::ViewAllocateWithoutInitializing;

one possible fix would be Kokkos::ViewAllocateWithoutInitializing => decltype(Kokkos::view_alloc(Kokkos::WithoutInitializing, "whatever")) actually that would not work, but a lambda would [](std::string label){return Kokkos::view_alloc(Kokkos::WithoutInitializing, label);}.

[dalg24]

@crtrott encouraged me to come up with a solution that does not break code. So here it is.

Make sure to drop 730adc2 before we merge. It is only there to demonstrate that the solution I propose works.

[DavidPoliakoff]

Looks good to me, though like Damien says we should drop the named commit when we merge

[dalg24]

Build before dropping the commit log is here

I added a unit test anyway.

[nliber]

Thoroughly looked through the changes. Looks good to me.