Add an operator controller for outreach mode

[beccawilcox001]

Add a second CommandXBoxController for the operator controller.

Update the drivetrain's default command so it the drivetrain can only move when the right trigger (of the operator controller) is held down.

In order to achieve this behavior, you'll have to add an operator controller to robot container, and change the drive default command so it checks if that button is held down before calling the drive subsystem command.

(mentor note: this may be a good use case for a ternary, even though they're 'banned')