As the RuntimeDeviceTracker is a per thread construct we now make
it explicit that you can only get a reference to the per-thread
version and can't copy it.
Rather than force all dispatchers to be templated on a device adapter,
instead use a TryExecute internally within the invoke to select a device
adapter.
Because this removes the need to declare a device when invoking a
worklet, this commit also removes the need to declare a device in
several other areas of the code.
Adding a new exception type `vtkm::cont::ErrorFilterExecution`. Unlike
existing exceptions, when thrown in `TryExecute`, this exception causes
the call to not attempt to execute on any other devices and let it be
thrown so that the application can catch it.
By using perfect forwarding we can reduce not only the amount of TryExecute
signatures, but we can enable the ability to pass temporary functors to
TryExecute.
At the same time we have optimized TryExecute by moving the string generation
code into a single function that is compiled into the vtkm_cont library.
The end result is that the vtkm_rendering library size has been reduced from
12MB to 11MB, and we shave off about 5% of our build time.
