Add support for interacting with Sequenced Gearshifts

[GreatFlamingFoo]

Description
Add a way to interact with Sequenced Gearshifts. I would like to have methods to add, remove, and edit steps in the current sequence. It would be nice to have a way to trigger the sequences without needing a separate redstone interface as well. It might also be nice to be able to just directly trigger steps programmatically without changing the existing sequence