[Search] Starting front-end

Starting to modify the front-end so that
the searchbar appears in the tree view
area. Made the tree holder have relative
position so that the searchbar is visibile
for now. (Later will be different.)

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

@@ -31,6 +31,7 @@
 @import "global";
 @import "fonts";
 @import "user-environ/layout";
+@import "search/layout";
 @import "fixed-position";
 @import "about";
 @import "text";