Make FileGridStorage class public

Author: TBlueF

core/src/main/java/de/bluecolored/bluemap/core/storage/file/FileGridStorage.java

@@ -44,7 +44,7 @@
 import java.util.stream.Stream;
 
 @RequiredArgsConstructor
-class FileGridStorage implements GridStorage {
+public class FileGridStorage implements GridStorage {
 
     private static final Pattern ITEM_PATH_PATTERN = Pattern.compile("x(-?\\d+)z(-?\\d+)");