[Frontend] Flex; Tweaks to slider knobs

open #889
- Converted TC elements to use flex
layout instead of abs pos;
- Knob size increased;
- Knob grippies added;

platform/commonUI/general/res/sass/_constants.scss

@@ -48,7 +48,7 @@ $uePaneMiniTabW: 10px;
 $uePaneMiniTabCollapsedW: 11px;
 $ueEditLeftPaneW: 75%;
 $treeSearchInputBarH: 25px;
-$ueTimeControlH: (33px, 15px, 15px);
+$ueTimeControlH: (33px, 18px, 20px);
 // Panes
 $ueBrowseLeftPaneTreeMinW: 150px;
 $ueBrowseLeftPaneTreeMaxW: 35%;