Remote project files don't have a reported file size until downloaded

[fuzyll]

See title. This is most frustrating when it turns out the file you tried to open is secretly 500mb in size and you're not on good internet.

This is an artifact of us having previously needed to pass all of this information over the plugin boundary, which is no longer an issue as of 4.1.5270-dev. We just need to do the refactor required to fix this.