Applies the given selector to all elements of the given collection and returns the max value of all elements. If an empty array is provided the function will return undefined

Example:

import { maxOf } from "https://deno.land/std@0.116.0/collections/mod.ts"
import { assertEquals } from "https://deno.land/std@0.116.0/testing/asserts.ts"

const inventory = [
     { name: "mustard", count: 2 },
     { name: "soy", count: 4 },
     { name: "tomato", count: 32 },
];
const maxCount = maxOf(inventory, (i) => i.count);

assertEquals(maxCount, 32);