Update shipitscript to support tasks that update the Nightly version in shipit if necessary

[gabrielBusta]

We should pass the version parameter of the Nightly graph through a task/payload for shipitscript following the build upload to the Mozilla archive. We can then allow the script to verify whether the Nightly version in shipit is up-to-date. If it is found to be outdated, the script could then do a version bump. This enhancement depends on mozilla-releng/shipit#1462