Better Route crypto helpers

Use the library helpers instead of reimplementing small security primitives.

use BetterRoute\Support\Crypto;
use BetterRoute\Support\CryptoEncoding;

$state = Crypto::token(32); // Base64URL by default.
$nonce = Crypto::token(32, CryptoEncoding::Base64Url);
$hex = Crypto::tokenHex(32);

$encoded = Crypto::base64UrlEncode($raw);
$decoded = Crypto::base64UrlDecode($encoded);

if (!Crypto::equals($expected, $provided)) {
    throw new \BetterRoute\Http\ApiException('Invalid token.', 401, 'invalid_token');
}