Improve setpoint pov

[KyleRAnderson]

Working towards resolving #125.

Summary of Changes

• Keep track of previously pressed correct POV button and run that command when it goes in between.
• Integrate this into lift setpoints.
• Added FluidTrigger, a trigger for buttons that are bound to fluid constants to make life easier.
• Added static utility methods to FluidButton to make its logic more accessible.

Testing Performed

Environment: Practice bot Ran the lift normally and then ran it purposefully going to the in-betweens and verified that it went to the right height.

[KyleRAnderson]

I'm going to want to test the FluidTrigger changes separately and merge it separately too, I already have a branch for it. This is therefore not ready.