feat: add CSRF token randomization

[kenjis]

Description

• To avoid BREACH attacks
• add Config\Security::$tokenRandomize (default is false)
• if Config\Security::$tokenRandomize is true
  • randomize CSRF token with random key and XOR

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[MGatner]

I'm not great with cryptography. This looks good to me but I would like it if someone else reviewed as well.

[kenjis]

I added User Guide.

[kenjis]

Thanks, guys!