WASHINGTON — A Republican megadonor paid two years of private school tuition for a child raised by Supreme Court Justice Clarence Thomas, who did not disclose the payments, a lawyer who has represented Thomas and his wife acknowledged Thursday.The revelation of tuition payments made by Dallas billionaire Harlan Crow is the latest example of Crow’s generosity to Thomas and his family that has raised questions about Thomas’ ethics and disclosure requirements more generally. The payments, along with the …