Add ability to update kernel parameters of a captured graph

See cudaGraphExecKernelNodeSetParams: https://developer.nvidia.com/blog/constructing-cuda-graphs-with-dynamic-parameters/

Reuse command object API so that set_param() can be used to update the kernel parameters of captured graphs?

• During graph capture, a Launch object would be returned from wp.launch() that can be used to update the kernel parameters after the graph is captured.