Refactor user session handling and permissions management

- Updated session variables to use 'authorization' array instead of 'username' for user identification across multiple files.
- Introduced a new function `getUserPermissions` to consolidate user permissions retrieval based on assigned roles.
- Modified API calls to use the new authorization structure and updated endpoints to v2.
- Enhanced language support by adding 'PL' to the list of supported languages.
- Cleaned up redundant code and improved session management during user login and registration processes.
- Added a new API endpoint for fetching user permissions based on user ID.

logfile.php

@@ -2,7 +2,7 @@
 defined(page_security_key) or exit;
 
 //Check if allowed
-if (isAllowed('logfile',$_SESSION['profile'],$_SESSION['permission'],'R') === 0){
+if (isAllowed('logfile',$_SESSION['authorization']['profile'],$_SESSION['authorization']['permission'],'R') === 0){
     header('location: index.php');
     exit;
 }