Decodes the given Uint8Array into a BigInt with LEB128.

import { decodeU64 } from "https://deno.land/std@0.166.0/encoding/varint/mod.ts";
const bytes = Uint8Array.from([221, 199, 1]);
const decodedValue = decodeU64(bytes);

// Do something with the decoded value
console.log(decodedValue === 25565n);