Allow for 'SameSite' cookie attribute and 'X-Frame-Options' header to be disabled to support framing

[ocram]

The X-Frame-Options header can already be disabled as documented:

\header_remove('X-Frame-Options');

Of course, this should be replaced with a proper option passed to this library so that setting and then removing the header is not necessary.

[ocram]

Disabling the SameSite attribute on cookies:

• vendor/delight-im/auth/src/UserManager.php
  • Replace Session::regenerate(true); with Session::regenerate(true, null);
• vendor/delight-im/auth/src/Auth.php
  • Replace @Session::start(); with @Session::start(null);
  • Replace Session::regenerate(true); with Session::regenerate(true, null);
  • After $cookie->setSecureOnly($params['secure']); append $cookie->setSameSiteRestriction(null); in all three (!) occurrences