Fix PHP 8.1 "strlen(null)" exception which blocks rendering project's Configure Menu page

Summary:
`strlen()` was used in Phabricator to check if a generic value is a non-empty string.
This behavior is deprecated since PHP 8.1. Phorge adopts `phutil_nonempty_string()` as a replacement.

Note: this may highlight other absurd input values that might be worth correcting
instead of just ignoring. If phutil_nonempty_string() throws an exception in your
instance, report it to Phorge to evaluate and fix that specific corner case.

Closes T15327

Test Plan: Applied this change (on top of D25166) and `/project/1/item/configure/` rendered in web browser.

Reviewers: O1 Blessed Committers, valerio.bozzolan

Reviewed By: O1 Blessed Committers, valerio.bozzolan

Subscribers: speck, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Maniphest Tasks: T15327

Differential Revision: https://we.phorge.it/D25173

src/applications/project/menuitem/PhabricatorProjectDetailsProfileMenuItem.php

@@ -31,7 +31,7 @@ final class PhabricatorProjectDetailsProfileMenuItem
     PhabricatorProfileMenuItemConfiguration $config) {
     $name = $config->getMenuItemProperty('name');
 
-    if (strlen($name)) {
+    if (phutil_nonempty_string($name)) {
       return $name;
     }