appview/pages: unify notice styles across settings pages

Signed-off-by: Anirudh Oppiliappan <[e-mail]>

appview/pages/templates/user/settings/keys.html

···
       </span>
     </button>
   </div>
+  <div id="settings-keys-success" class="text-green-500 dark:text-green-400"></div>
   <div id="settings-keys" class="text-red-500 dark:text-red-400"></div>
 </form>
 {{ end }}

appview/pages/templates/user/settings/notifications.html

···
         {{ i "loader-circle" "w-4 h-4 animate-spin hidden group-[.htmx-request]:inline" }}
       </button>
     </div>
-    <div id="settings-notifications-success"></div>
-
-    <div id="settings-notifications-error" class="error"></div>
+    <div id="settings-notifications-success" class="text-green-500 dark:text-green-400"></div>
+    <div id="settings-notifications-error" class="text-red-500 dark:text-red-400"></div>
   </form>
 {{ end }}