Fix PHP 8.1 "strlen(null)" exception creating a Legalpad text master
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. ``` ERROR 8192: strlen(): Passing null to parameter #1 ($string) of type string is deprecated at [/var/www/html/phorge/phorge/src/applications/legalpad/xaction/LegalpadDocumentTitleTransaction.php:22] ``` Closes T16505 Test Plan: * Create a Legalpad at http://phorge.localhost/legalpad/edit/ * Go to http://phorge.localhost/feed/transactions/ Reviewers: O1 Blessed Committers, mainframe98 Reviewed By: O1 Blessed Committers, mainframe98 Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno Maniphest Tasks: T16505 Differential Revision: https://we.phorge.it/D26766