LPS-38136 - Center search box and button group in navbar

LPS-38136 - Fix min-height on control panel dockbar and SF

LPS-38136 - Remove margins causing alignment issues in search bar on document and media portlet

LPS-38136 - Remove box shadow under search button

LPS-38136 - Move background back to custom_common.css

LPS-38136 - Change background-color to background