Media: ensure JavaScript initialized when media edit screen is loaded directly.

Fix a JavaScript error when the media edit screen is loaded directly via a url such as `/wp-admin/post.php?post={post_id}&action=edit&image-editor`. Add a check in `imgLoaded` for `this.hold.sizer` which is set up during initialization and required for the cropping tool. Call `init` if this is undefined.

Props NoseGraze.
Fixes #38138.


git-svn-id: https://develop.svn.wordpress.org/trunk@40020 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/js/image-edit.js

@@ -573,6 +573,11 @@
 	imgLoaded : function(postid) {
 		var img = $('#image-preview-' + postid), parent = $('#imgedit-crop-' + postid);
 
+		// Ensure init has run even when directly loaded.
+		if ( 'undefined' === typeof this.hold.sizer ) {
+			this.init( postid );
+		}
+
 		this.initCrop(postid, img, parent);
 		this.setCropSelection(postid, 0);
 		this.toggleEditor(postid, 0);