Add support protection of worksheet by a specific hash algorithm

[reijnnn]

This is:

- [ ] a bugfix
- [x] a new feature

Checklist:

• Changes are covered by unit tests
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change
• Documentation is updated as necessary

Why this change is needed?

This feature allows you to protect the worksheet using a specific hash algorithm (for example, md5, sha-256) and allows you to check the correct password when you open a document

More info

ISO Write Protection Method

Example write

<?php
require __DIR__ . '/vendor/autoload.php';
use PhpOffice\PhpSpreadsheet\Shared\PasswordHasher;
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;

$password = 'PhpSpreadsheet';
$salt = PasswordHasher::generateSalt();
$spinCount = 10000;

$spreadsheet = new Spreadsheet();
$worksheet = $spreadsheet->getActiveSheet();
$worksheet->getProtection()->setSheet(true);
$worksheet->getProtection()->setHashValue(PasswordHasher::hashPassword($password, PasswordHasher::ALGORITHM_SHA_256, $salt, $spinCount));
$worksheet->getProtection()->setAlgorithmName(PasswordHasher::ALGORITHM_SHA_256);
$worksheet->getProtection()->setSaltValue($salt);
$worksheet->getProtection()->setSpinCount($spinCount);

$writer = new Xlsx($spreadsheet);
$writer->save('tst_write_example.xlsx');

Example read

<?php
require __DIR__ . '/vendor/autoload.php';
use PhpOffice\PhpSpreadsheet\Shared\PasswordHasher;
use PhpOffice\PhpSpreadsheet\Reader\Xlsx;

$reader = new Xlsx();
$spreadsheet = $reader->load('tst_write_example.xlsx');
$worksheet = $spreadsheet->getActiveSheet();

$password = 'PhpSpreadsheet';

if($worksheet->getProtection()->isProtectionEnabled()) {
   if($worksheet->getProtection()->getPassword()) {
      $hashPassword = $worksheet->getProtection()->getPassword();
      if($hashPassword == PasswordHasher::hashPassword($password)) {
         echo "[1] password is correct";
      } else {
         echo "[1] password is incorrect";
      }
   }

   if($worksheet->getProtection()->getHashValue()) {
      $hashPassword = $worksheet->getProtection()->getHashValue();
      $algorithmName = $worksheet->getProtection()->getAlgorithmName();
      $saltValue = $worksheet->getProtection()->getSaltValue();
      $spinCount = $worksheet->getProtection()->getSpinCount();
      if($hashPassword == PasswordHasher::hashPassword($password, $algorithmName, $saltValue, $spinCount)) {
         echo "[2] password is correct";
      } else {
         echo "[2] password is incorrect";
      }
   }
} else {
   echo "Protection is disabled";
}

[PowerKiKi]

Merged with modification in b9a5966