Fast Implementation of Base58 encoding

Fast implementation of base58 encoding in Go.

Base algorithm is adapted from https://github.com/trezor/trezor-crypto/blob/master/base58.c

Benchmark

• Trivial - encoding based on big.Int (most libraries use such an implementation)
• Fast - optimized algorithm provided by this module

cpu: Apple M4
BenchmarkTrivialBase58Encoding-10       	  712528	      1539 ns/op
BenchmarkFastBase58Encoding-10          	 6090552	       193.7 ns/op

BenchmarkTrivialBase58Decoding-10       	 1539550	       767.5 ns/op
BenchmarkFastBase58Decoding-10          	18001034	        64.68 ns/op

cpu: AMD Ryzen 7 PRO 4750U
BenchmarkTrivialBase58Encoding-16                 239527              5149 ns/op
BenchmarkFastBase58Encoding-16                   5029388               252.6 ns/op

BenchmarkTrivialBase58Decoding-16                 880732              1434 ns/op
BenchmarkFastBase58Decoding-16                   9524245               151.9 ns/op

Encoding - faster by 8 times

Decoding - faster by 12 times

Usage example

package main

import (
	"fmt"
	"github.com/mr-tron/base58"
)

func main() {

	encoded := "1QCaxc8hutpdZ62iKZsn1TCG3nh7uPZojq"
	num, err := base58.Decode(encoded)
	if err != nil {
		fmt.Printf("Demo %v, got error %s\n", encoded, err)	
	}
	chk := base58.Encode(num)
	if encoded == string(chk) {
		fmt.Printf ( "Successfully decoded then re-encoded %s\n", encoded )
	} 
}