Allow statusbar and information panel to stat with KIO::StatRecursiveSize

Summary: Needed after D28901 to ensure we get the UDS_RECURSIVE_SIZE out of the stat calls.

Test Plan: Trash size is visible in status bar and information panel again.

Reviewers: ngraham, dfaure, #dolphin

Reviewed By: dfaure

Subscribers: kfm-devel

Tags: #dolphin

Differential Revision: https://phabricator.kde.org/D28950