Add new views and styles for music application

- Created new CSS files for styling the application, including home.css and style.css.
- Implemented 403 and 404 error views with appropriate messages and navigation.
- Developed a dump view to display deleted elements with restoration options.
- Enhanced home view to include music search functionality and display results.
- Added listplay view for managing music playlists, including creation and deletion options.
- Implemented loadmusic view for uploading new music with necessary fields.
- Created login and register views for user authentication.
- Developed sound view to display individual music tracks with playback controls and options for liking and deleting.
- Updated menu view to include navigation links based on user authentication status.

request/post/listplay.post.php

@@ -0,0 +1,14 @@
+<?php
+    if(Session::Auth()){
+        if(isset($_POST['txtListName'])){
+            $listplayer->newList($_POST['txtListName']);
+        }elseif(isset($_POST['deleteList'])){
+            $listplayer->deleteList($_POST['deleteList']);
+        }elseif(isset($_POST['idMusic']) && isset($_POST['idList'])){
+            $listplayer->addMusicToList($_POST['idList'], $_POST['idMusic']);
+            $view = "$view&listmusic=" . md5($_POST['idList']);
+        }
+    }
+
+    header("location: ./?view=$view");
+?>