Get simple 3.3.16 support for php 8.0

[islander]

Fixes in GetSimple core:

/admin/inc/basic.php: line 85:
  $text = mb_convert_encoding($text ?? "",'HTML-ENTITIES',$from_enc);

/admin/inc/cookie_functions..php: line 23:
  return setcookie($id, $value, $expire, $cookie_path, $cookie_domain ??"", $cookie_secure??"", $cookie_httponly);

/admin/inc/cookie_functions..php: line 35:
return setcookie($id,false,1,$cookie_path,$cookie_domain??"",$cookie_secure??"", $cookie_httponly);

@Knobbles Thanks for the info!
The first fix you included (/admin/inc/basic.php: line 85) should say "line 65"

I will try to incorporate these fixes into one of the above patch files and post it here as soon as I can get some time.
I will also try to see if I can if I can create a Pull Request via Github to see if that would help with an official version.
But I really dont know, as it seems that all the official peeps are busy with other things.