refs #14565 - merge vf release branch 5.1 in finc-master v5

* uncomments grunt compile error at themes/bootstrap3/scss/components/offcanvas .btn elements +28 for the moment
* updates composer.lock

composer.lock

@@ -2130,7 +2130,7 @@
                 },
                 {
                     "name": "Gert de Pagter",
-                    "email": "backendtea@gmail.com"
+                    "email": "BackEndTea@gmail.com"
                 }
             ],
             "description": "Symfony polyfill for ctype functions",

themes/bootstrap3/scss/components/offcanvas.scss

@@ -3,8 +3,9 @@ $offcanvas-offset: 80vw !default;  // Width of open menu
 .offcanvas-overlay { display: none; }
 
 .search-filter-toggle {
-  @extend .btn;
+  /*@extend .btn;
   @extend .btn-default;
+  */
   margin-top: 1rem;
   margin-bottom: 1rem;
 }
@@ -24,8 +25,12 @@ $offcanvas-offset: 80vw !default;  // Width of open menu
 
   .offcanvas .close-offcanvas { display: block; }
   .search-filter-toggle {
+    /* refs #14565 uncommented by vf 5.1 update
+    grunt says that you may not @extend an outer selector from within @media.
+    @to-do fixing bug
     @extend .btn;
     @extend .btn-default;
+    */
     margin-top: 1rem;
     margin-bottom: 1rem;
   }