`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.
However, the parameter `$item_id` is a numeric value when populated.
Thus replace `strlen()` with `phutil_nonempty_scalar()` as `phutil_nonempty_string()` could break a Conduit API consumer sending a numeric value.
Note: this may highlight other absurd input values that might be worth correcting
instead of just ignoring. If phutil_nonempty_scalar() throws an exception in your
instance, report it to Phorge to evaluate and fix that specific corner case.
Closes T15317