Removes less code that uses frontend definitions in an adminhtml file. Fixes #775

Author: hostep

app/code/Magento/PageBuilder/view/adminhtml/web/css/source/content-type/products/_default.less

@@ -27,10 +27,6 @@
         margin-left: -20px;
     }
 
-    .product-items {
-        &:extend(.abs-reset-list all);
-    }
-
     .product-item {
         display: inline-block;
         max-width: 100%;
@@ -40,8 +36,6 @@
         vertical-align: top;
         width: 200px;
 
-        &:extend(.abs-add-box-sizing all);
-
         a,
         button,
         .swatch-attribute-options {
@@ -192,7 +186,6 @@
             }
 
             &.towishlist {
-                &:extend(.abs-actions-addto all);
                 .lib-icon-font-symbol(
                     @_icon-font-content: @icon-wishlist-full,
                     @_icon-font-position: before
@@ -209,7 +202,6 @@
     }
 
     .product-item-name {
-        &:extend(.abs-product-link all);
         -moz-hyphens: auto;
         -ms-hyphens: auto;
         -webkit-hyphens: auto;
@@ -274,7 +266,6 @@
         overflow: hidden;
         position: relative;
         z-index: 1;
-        &:extend(.abs-reset-image-wrapper all);
     }
 
     .product-image-container {