use css truncate everywhere and remove StringUtils.truncate function (#513)

Co-authored-by: robs <git@robs.social>

lib/pinchflat_web/controllers/searches/search_html/show.html.heex

@@ -1,6 +1,6 @@
 <div class="mb-6 flex gap-3 flex-row items-center justify-between">
-  <h2 class="text-title-md2 font-bold text-black dark:text-white">
-    Results for "{StringUtils.truncate(@search_term, 50)}"
+  <h2 class="text-title-md2 font-bold text-black dark:text-white truncate">
+    Results for "{@search_term}"
   </h2>
 </div>