[Glitch] Add message telling FTS is disabled when no toot can be found because of this

Port ca8944728f to glitch-soc

app/javascript/flavours/glitch/styles/components/search.scss

@@ -78,6 +78,11 @@
   font-weight: 500;
 }
 
+.search-results__info {
+  padding: 10px;
+  color: $secondary-text-color;
+}
+
 .trends {
   &__header {
     color: $dark-text-color;