[Frontend] Hiding non-functional items; padding adjustments

WTD-1163
WTD-1146
New CSS to hide non-functional elements, including browse.top-bar with search elements;
Adjusted spacing, mainly in .contents CSS class;

platform/commonUI/general/res/templates/controls/action-button.html

@@ -1,4 +1,4 @@
-<a class="t-btn l-btn s-btn s-icon-btn s-very-subtle"
+<a class="t-btn l-btn s-btn s-icon-btn s-very-subtle key-{{parameters.action.getMetadata().key}}"
    ng-class="{ labeled: parameters.labeled }"
    title="{{parameters.action.getMetadata().description}}"
    ng-click="parameters.action.perform()">