For shippable builds phase 2, we want to eliminate any confusion between lingering 'nightly' entries in treeherder and taskgraph.
This work should also encompass what is possible to align between the Nightly release process and the Beta/Release/ESR release process.
Work will be split out into dependent bugs, as much of it is relatively stand alone work items.
Original shippable bug still has open "blocks" deps on 1563663, and 1501898; and was listed as "depends-on" 1416538. Adding them to this bug so that they are not lost as correlation on the work.