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

src/plugins/displayLayout/components/SubobjectView.vue

@@ -107,7 +107,7 @@
 
 <script>
     import ObjectView from '../../../ui/components/layout/ObjectView.vue'
-    import ContextMenuDropDown from './contextMenuDropDown.vue';
+    import ContextMenuDropDown from '../../../ui/components/controls/contextMenuDropDown.vue';
     import LayoutFrame from './LayoutFrame.vue'
 
     const MINIMUM_FRAME_SIZE = [320, 180],

src/plugins/displayLayout/components/contextMenuDropDown.vue

@@ -1,14 +0,0 @@
-<template>
-    <div class="c-so-view__context-actions c-disclosure-button"
-         @click="showContextMenu"></div>
-</template>
-
-<script>
-import contextMenu from '../../../ui/components/mixins/context-menu-gesture'
-
-export default {
-    props: ['objectPath'],
-    mixins: [contextMenu],
-}
-</script>
-