update preview action to use new action registry

* Support category arrays for legacy actions

* Fixed object path listener. Removed old context menus

* Removed old fullscreen action and Screenfull dependency

* Restore confirmation dialog on remove

* Restored tests

* Remove unused legacy policies

* WIP re-implementation of Preview action

* WIP for Charles to take a look at flex issues

* Disable legacy preview action

* Style and markup fixes for new Preview

- LegacyViewProvider modded to wrap legacy elements in .u-contents div;
- Added selector that automatically defines display: contents on
`no-class` divs injected into __object-view;
- Unit tested with legacy and new components (telem tables, plot view,
Notebook, etc.)

* Tweak z-indexes, fix open in new tab action, add 'done' button

* Removed legacy action

* reuse contextMenuDropDown component

platform/commonUI/dialog/src/OverlayService.js

@@ -95,7 +95,10 @@ define(
 
             // Create the overlay element and add it to the document's body
             element = this.$compile(TEMPLATE)(scope);
-            this.findBody().prepend(element);
+            
+            // Append so that most recent dialog is last in DOM. This means the most recent dialog will be on top when
+            // multiple overlays with the same z-index are active.
+            this.findBody().append(element);
 
             return {
                 dismiss: dismiss