Add function to get random nature, add shiny rate to library settings

tests/common/library_loader.rs

@@ -65,7 +65,7 @@ pub fn load_library() -> LoadResult {
     let species_load_time = t2 - t1;
 
     let data = StaticDataImpl::new(
-        Box::new(LibrarySettingsImpl::new(100)),
+        Box::new(LibrarySettingsImpl::new(100, 100)),
         species,
         moves,
         items,