On Windows, encode file paths as UTF-16 before trying to open the file for reading/writing. This introduces a new class `blender::fstream`, which wraps `std::fstream` and provides this UTF-16 encoding. This class should also be used in other areas, like the Alembic importer/exporter. Manifest Task: T93960 Reviewed By: JacquesLucke Differential Revision: https://developer.blender.org/D13633