fix: Use the new #classicwebcam_container

Since OctoPrint/OctoPrint#4628 we need to use `#classicwebcam_container` otherwise all controls and text information provided by this plugin is `display:none`.

octoprint_fullscreen/static/js/fullscreen.js

@@ -33,13 +33,18 @@ $(function() {
 			var $webcam = $('#webcam_image');
 			var $info = $('#fullscreen-bar');
 
-			var containerPlaceholder = document.getElementById('webcam') ? '#webcam' : '#webcam_container';
+			var containerPlaceholder = document.querySelector('#webcam,#webcam_container,#classicwebcam_container');
+			if (!containerPlaceholder) {
+				return;
+			}
+
+			var containerPlaceholderSelector = `#${containerPlaceholder.id}`;
 			if ($('.webcam_fixed_ratio').length > 0) {
 				$container = $(containerPlaceholder + ' .webcam_fixed_ratio');
 				$fullscreenContainer = $(containerPlaceholder + ' #webcam_rotator');
 			} else {
 				$container = $(containerPlaceholder + ' #webcam_rotator');
-				$fullscreenContainer = $(containerPlaceholder + ' #webcam_container');
+				$fullscreenContainer = $(containerPlaceholder + ' #classicwebcam_container');
 			}
 
 			var touchtime = 0;