Global filtering (#2434)

* Adds global filtering
* Markup changes to support global filtering
* Adds toggle button
* Added row item spacing for tree__item in mct-tree.vue;
* Significant mods to tree-based properties displays in Inspector:
* Padding in c-object-label tweaked;
* Class naming normalized, legacy classes removed;
* Layout fixed for filters in Browse mode

src/ui/components/ObjectLabel.vue

@@ -20,7 +20,7 @@
         align-items: center;
         flex: 1 1 auto;
         overflow: hidden;
-        padding: $interiorMarginSm;
+        padding: $interiorMarginSm 1px;
         white-space: nowrap;
 
         &__name {