The newer version of `ArrayHandle` no longer supports different types of
portals for different devices. Thus, the `ReadPortalType` and
`WritePortalType` are sufficient for all types of portals across all
devices.

This significantly simplifies supporting execution objects on devices,
and thus this change also includes many changes to various execution
objects to remove their dependence on the device adapter tag.

Marked the old versions of PrepareFor* that do not use tokens as
deprecated and moved all of the code to use the new versions that
require a token. This makes the scope of the execution object more
explicit so that it will be kept while in use and can potentially be
reclaimed afterward.

This work updates Gunther Contour tree work to be parallel.
With contributions from: @oruebel, @dcamp and @sujin.philip.

Diy Upstream authored Apr 09, 2019 and Maynard, Robert committed Apr 09, 2019

Code extracted from:

    https://gitlab.kitware.com/third-party/diy2.git

at commit f7a68da4fbe93ae7a8699b66f125a98ace842998 (for/vtk-m).

Now that the dispatcher does its own TryExecute, filters do not need to
do that. This change requires all worklets called by filters to be able
to execute without knowing the device a priori.