ODT writer: Fix handling of `*.xml` stylesheets.
According to the ODT writer documentation, the "stylesheet" setting should work with either "styles.odt" or "styles.xml" files.
Fix errors with "*.xml" style files [bugs:#494]. Thanks to Paul Kishimoto for report and analysis.
Authored by: milde 2024-10-20
Parent: [r9952]
Child: [r9954]