[Frontend] In-progress checkin: color palette SASS

WTD-847
Significant markup and CSS for color palette support;

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

@@ -15,6 +15,7 @@
 @import "icons";
 @import "lists/tabular";
 @import "controls/buttons";
+@import "controls/color-palette";
 @import "controls/controls";
 @import "controls/lists";
 @import "controls/menus";