Check labels styles

We are use a display: block style for labels containing check boxes inside
them, and the label has a width of 100%.

This means that clicking on the blank space on the right of the label text
will check/uncheck the checkbox. To avoid this behaviour we modify the
"display" attribute of the labels.

In order to prevent unexpected behaviour in terms_of_service form labels,
we add specific css for this case when define a checkbox within the
.actions class.

app/assets/stylesheets/layout.scss

@@ -1063,6 +1063,10 @@ form {
     line-height: $line-height;
   }
 
+  .checkbox-label {
+    display: table;
+  }
+
   fieldset legend {
     font-weight: bold;
   }

app/assets/stylesheets/mixins/forms.scss

@@ -170,6 +170,11 @@
     @include breakpoint(medium) {
       width: 75%;
     }
+
+    label {
+      margin-left: auto;
+      margin-right: auto;
+    }
   }
 }