Add blocks button on floating menu not fitting width

When on a small screen, the add blocks button in the floating
menu on edit page has a gap on the right. Fix adds 100% to the
button and its wrapper so it will fill up the space just like
the buttons below it.

behatnotneeded

Change-Id: Ia20003a4a8115ac6edae5a1d4ac8a4e00557c2de

htdocs/theme/raw/sass/components/_btn.scss

@@ -21,7 +21,7 @@
 .btn-primary:not(:disabled):not(.disabled).active, .btn-primary:not(:disabled):not(.disabled):active, .show>.btn-primary.dropdown-toggle {
     color: inherit;
     background-color: $gray-400;
-    border-color: $btn-secondary-border;;
+    border-color: $btn-secondary-border;
     box-shadow: none;
 }
 
@@ -499,6 +499,13 @@ td.action-list-copy {
 .pageactions {
     margin-right: -1px;
 
+    .content-toolbar {
+        width: 100%;
+        .btn {
+            width: 100%;
+        }
+    }
+
     .btn-group-vertical .btn {
         &:last-child {
             border-bottom-right-radius: 0;