MC-3571: Implement overlay for MC-1405

Add icon variables

Author: danmooney2

app/code/Magento/PageBuilder/view/adminhtml/web/css/source/_icons.less

@@ -37,6 +37,8 @@
 @icon-pagebuilder-align-right__content: '\e91c';
 @icon-pagebuilder-variable__content: '\e917';
 @icon-pagebuilder-widgets__content: '\e918';
+@icon-pagebuilder-show__content: '\e91f';
+@icon-pagebuilder-hide__content: '\e920';
 
 .icon-pagebuilder-accordion:before {
     content: @icon-pagebuilder-accordion__content;
@@ -168,6 +170,13 @@
     content: @icon-pagebuilder-widgets__content;
 }
 
+.icon-pagebuilder-show:before {
+    content: @icon-pagebuilder-show__content;
+}
+ .icon-pagebuilder-hide:before {
+    content: @icon-pagebuilder-hide__content;
+}
+
 .icon-admin-pagebuilder-remove {
     .abs-icon;
     &:before {