Restore top/bottom menu location setting (#1123)

* Rename floating to top

* Adjust teleport target

* Fix dropdown direction for bottom menubar

* Fix z-index

src/assets/css/style.css

@@ -126,7 +126,8 @@ body {
   /* Span across all columns */
   grid-column: 1/-1;
   grid-row: 3;
-  z-index: 10;
+  /* Bottom menu bar dropdown needs to be above of graph canvas splitter overlay which is z-index: 999 */
+  z-index: 1000;
   display: flex;
   flex-direction: column;
 }