"Re-create world" button should copy the datapacks folder

Currently, "re-create world" copies the seed and world generation options, but the datapacks folder does not seem to be considered at all. The "re-create world" option should copy the datapacks folder from the source world.

Ideally, this would copy the directory exactly, so if the directory (or contents of the directory) are symlinks, they would be copied as symlinks.