Changed padding & background color for highlighted notes

Closes #12453

app/assets/stylesheets/framework/timeline.scss

@@ -5,7 +5,7 @@
   padding: 0;
 
   .timeline-entry {
-    padding: $gl-padding 0;
+    padding: $gl-padding $gl-btn-padding;
     border-color: $table-border-color;
     color: $gl-gray;
     border-bottom: 1px solid $border-white-light;

app/assets/stylesheets/framework/variables.scss

-$hover: #faf9f9;
+$hover: #f4f8fe;
 $gl-text-color: #54565B;
 $gl-text-green: #4A2;
 $gl-text-red: #D12F19;