El Toro to Flipper Conversions

From David:

Went into RoboBuilder and made a new subsystem for the flipper. Moved
the "eltoro" updown motor into the flipper, where it now belongs, and
put proper limit switches in.

Added the final limit switch of the bot into the code using RoboBuilder
and renamed the limit switches to make sense.

In the code: Deleted any classes of and relating to the raising and
lowering of eltoro. Replaced them with Raising and Lowering of the
Flipper, and made a new EjectBall class. No code has been written for
any of the new classes, and that does need to be done.
Raise/Lower Flipper

Implemented the Raise and LowerFlipper commands.

Updated Official.yml to remove the old El Toro raise and lower commands
-- and cleaned up the El Toro subsystem to match.

Deleted Delay, which was a) incompletely implemented and b) duplicated
Pause.
Simplify! Subsystematize!

Stripped out a bunch of extraneous commands that were only needed so
that we could have a big, fancy command group that did what we really
wanted. Converted those commands into subsystem methods that could be
called by a (much simpler) command that did what we wanted.

Reimplemented Flipper and El Toro subsystems to use this approach. Note
the lack of references to RobotMap -- we're actually now using the
subsystems as they were meant to be used!
Added EjectBall to RobotBuilder

What subsystem handles this? Is this the flipper?
Started implementing Catapult subsystem

…but I don't know enough about the limit switch setup to finish it.
Where is the clutch limit switch? Do we have an encoder?

Also: does the Flipper eject the ball? If so, how?