fix: Drag preview issues (#905)

* Changed drag preview position from `left: -100000px;` to `z-index: -1;`

* Fixed `appendChild` being called instead of `removeChild`

Author: matthewlipski

packages/core/src/editor/editor.css

@@ -62,7 +62,7 @@ Tippy popups that are appended to document.body directly
 
 .bn-drag-preview {
   position: absolute;
-  left: -100000px;
+  z-index: -1;
 }
 
 /* Give a remote user a caret */

packages/core/src/extensions/SideMenu/SideMenuPlugin.ts

@@ -158,7 +158,7 @@ function unsetDragImage(rootEl: Document | ShadowRoot) {
     if (rootEl instanceof ShadowRoot) {
       rootEl.removeChild(dragImageElement);
     } else {
-      rootEl.body.appendChild(dragImageElement);
+      rootEl.body.removeChild(dragImageElement);
     }
 
     dragImageElement = undefined;