StepButtons is a functional component that renders a set of buttons for navigation in a multi-step process. It renders a "Previous" button if the current step is greater than 1. It renders a "Next" button if the current step is between 1 and 4 (or 3 if there is no extra step). It renders a "Create Course" button if the current step is the last step (4 or 5 depending on whether there is an extra step).