added backend delete functionality

backend/filedelete.php

+<?php
+
+include_once("database.php");
+$postData = file_get_contents("php://input");
+
+if (isset($postData) && !empty($postData)) {
+  $request = json_decode($postData);
+  $username = trim($request->username);
+  $data = trim($request->text);
+  $filename = trim($request->filename);
+  $lang = trim($request->language);
+  $path = '../users/' . $username . '/' . trim($request->path) . '/' . $filename . $lang;
+
+  if (unlink($path)) {
+    $msg = "file successfully deleted";
+    clearstatcache();
+    echo json_encode($msg);
+  }
+  else {
+        http_response_code(404);
+  }
+
+
+}
+?>