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 T15305 Test Plan: Applied these two changes (on top of `D25144`, `D25145`, `D25146`, `D25147`, `D25150`, `D25151`, `D25152`, `D25153`, `D25154`)) and "Use Results -> Add Panel to Dashboard" overlay dialog finally 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: T15305 Differential Revision: https://we.phorge.it/D25155