style: remove display name helper in member overview for UX

lib/mv_web/live/member_live/index.html.heex

@@ -129,12 +129,7 @@
         """
       }
     >
-      {if MvWeb.MemberLive.Index.blank?(member.first_name) &&
+      {member.first_name}
-            MvWeb.MemberLive.Index.blank?(member.last_name) do
-        MvWeb.MemberLive.Index.display_name(member)
-      else
-        member.first_name
-      end}
     </:col>
     <:col
       :let={member}