Fix query and export to correctly handle syndicated

[RhetTbull]

Currently there's no way to filter for all photos + only syndicated photos that have been saved to the library. See this discussion on reddit. Perhaps the best option is to exclude photos that are syndicated but not saved to the library by default for both query and export then include them only if new flag --include-syndicated is passed. Since these don't show in the library this is probably the principle of least surprise.