[Bugfix:Submission] Bulk upload encode query params (Submitty#11228)

Fixes Submitty#11185 
If a file uploaded by TA/instructor to a bulk upload pdf file gradeable
contains a space in the filename, the error is unhelpful.

----------------------

In addition to space, we currently have the following disallowed
characters, and I have included space as well:

![Screenshot 2024-12-04
042041](https://github.com/user-attachments/assets/c0ebefe3-d7cb-4173-b771-fe9b2dcf6345)

Added documentation for filename requirements :

![Screenshot 2024-12-04
034250](https://github.com/user-attachments/assets/a7086f4e-9717-4eef-a68a-8835bfe6d0c7)

Error message is also fixed : 

![Screenshot 2024-12-04
042821](https://github.com/user-attachments/assets/d5bf33f0-fcb0-4bc1-88bf-ffa2c7e46e6f)

Author: MjStar24

site/app/controllers/student/SubmissionController.php

@@ -492,7 +492,13 @@ public function ajaxBulkUpload($gradeable_id) {
                 // so we are using a python script via CGI to validate whether file is divisible by num_page or not.
                 $pdf_full_path = FileUtils::joinPaths($pdf_path, $job_data["timestamp"], $job_data["filename"]);
                 $ch = curl_init();
-                curl_setopt($ch, CURLOPT_URL, $this->core->getConfig()->getCgiUrl() . "pdf_page_check.cgi?pdf_path={$pdf_full_path}&num_page={$num_pages}&file_name={$job_data['filename']}");
+                curl_setopt($ch, CURLOPT_URL, $this->core->getConfig()->getCgiUrl() . "pdf_page_check.cgi?" . http_build_query(
+                    [
+                        'pdf_path' => $pdf_full_path,
+                        'num_page' => $num_pages,
+                        'file_name' => $job_data['filename']
+                    ]
+                ));
                 curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
                 $output = curl_exec($ch);
                 curl_close($ch);