Add cancel snooze

- Add common request validation function

src/public/request/prayed.php

@@ -1,16 +1,11 @@
 <?php declare(strict_types=1);
 
-use MyPrayerJournal\{Auth, History, RecurrencePeriod, Request, RequestAction, Table, UI};
+use MyPrayerJournal\{History, RecurrencePeriod, RequestAction, Table, UI};
 use BitBadger\PDODocument\Patch;
 
 require '../../start.php';
-if ($_SERVER['REQUEST_METHOD'] <> 'PATCH') not_found();
-
-Auth::requireUser(false);
-
-$req = Request::byId($_GET['id']);
-if (!$req) not_found();
 
+$req = validate_request($_GET['id'], ['PATCH'], false);
 $now = new DateTimeImmutable('now');
 
 array_unshift($req->history, new History($now->format('c'), RequestAction::Prayed));