Use spot colours again to match Design system styles and avoid missing hover effect with standard theme (#10584)

frontend/src/app/spot/styles/sass/components/link.sass

@@ -1,7 +1,7 @@
 .spot-link
   @include unset-button-styles
   display: inline
-  color: var(--content-link-color)
+  color: $spot-color-main
   text-decoration: none
   cursor: pointer
 
@@ -11,7 +11,7 @@
   &:hover,
   &:active,
   &:focus
-    color: var(--content-link-hover-active-color)
+    color: $spot-color-main-dark
     text-decoration: none
 
   &_danger