Add support for passing rvalue of GridCreator to VtkReader
Similar to !61 (merged) this MR allows to pass rvalues of GridCreators to the VtkReader. This allows to write
auto reader = VtkReader(ContinuousGridCreator<Grid>{});Similar to !61 (merged) this MR allows to pass rvalues of GridCreators to the VtkReader. This allows to write
auto reader = VtkReader(ContinuousGridCreator<Grid>{});