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.

api/v2/get/user_permissions.php

@@ -0,0 +1,70 @@
+<?php
+defined($security_key) or exit;
+
+//------------------------------------------
+// User Role Assignments
+//------------------------------------------
+//Connect to DB
+$pdo = dbConnect($dbname);
+
+//------------------------------------------
+//NEW ARRAY
+//------------------------------------------
+$criterias = [];
+$user_permissions = [];
+
+//------------------------------------------
+//Check for $_GET variables and build up clause
+//------------------------------------------
+if(isset($get_content) && $get_content!=''){
+    //GET VARIABLES FROM URL
+    $requests = explode("&", $get_content);
+    //Check for keys and values
+    foreach ($requests as $y){
+        $v = explode("=", $y);
+        //INCLUDE VARIABLES IN ARRAY
+        $criterias[$v[0]] = $v[1];
+    }
+}
+
+$user_key = $criterias['userkey'] ?? null;
+
+if (!$user_key) {
+    http_response_code(400);
+    exit(json_encode(['error_code' => 'API_INPUT_1','error' => 'user_key is required']));
+}
+
+//GET USER_DATA
+$stmt = $pdo->prepare('SELECT * FROM users WHERE userkey = ?');
+$stmt->execute([$user_key]);
+
+if ($stmt->rowCount() == 1) {
+    //Get results
+    $user_data = $stmt->fetch();
+
+    //GET DATA
+    $user_permissions['id'] = $user_data['id'];
+    $user_permissions['email'] = $user_data['email'];
+    $user_permissions['partnerhierarchy'] = $user_data['partnerhierarchy']; //clean;
+    $user_permissions['permission'] = userRights($user_data['view']);
+    $user_permissions['profile'] = getProfile($user_data['settings'],userRights($user_data['view']));
+
+    //NEW DATA REPLACING PROFILE AND LATER PERMISSION ABOVE
+    $user_permissions['permissions'] = getUserPermissions($pdo, $user_data['id']);
+
+    if (!$user_permissions['permissions']) {
+        http_response_code(404);
+        exit(json_encode(['error_code' => 'API_NOT_FOUND','error' => 'No permissions found']));
+    }
+
+    //+++++++++++++++++++++++++++++++++++++++++++
+    //Return as JSON
+    //+++++++++++++++++++++++++++++++++++++++++++
+    echo json_encode($user_permissions);
+}
+else {
+    http_response_code(404);
+    exit(json_encode(['error_code' => 'API_NOT_FOUND','error' => 'User not found']));
+}
+
+?>