Given an integer array arr, and an integer target, return the number of tuples i, j, k such that i < j < k and arr[i] + arr[j] + arr[k] == target.
As the answer can be very large, return it modulo 10^9 + 7.
3 <= arr.length <= 30000 <= arr[i] <= 1000 <= target <= 300arr = [1,1,2,2,3,3,4,4,5,5], target = 820arr = [1,1,2,2,2,2], target = 512arr = [2,1,3], target = 61