Given two binary search trees root1 and root2, return a list containing all the integers from both trees sorted in ascending order.
[0, 5000]-10^5 <= Node.val <= 10^5root1 = [2,1,4], root2 = [1,0,3][0,1,1,2,3,4]root1 = [1,null,8], root2 = [8,1][1,1,8,8]