Should Parla tasks/contexts also setup stream handles for numba?

[wlruys]

Inspired by the recent discussion on Slack around https://gist.github.com/leofang/4a043e5d94b4702d04fde2b9e7dcebbd and passing the current stream to numba kernels.

Looking forward, would it make sense to provide a local variable within a task for this as well to prevent the user from creating and destroying these stream wrappers themselves?