世界管理新增删除世界功能 (#4263)

Co-authored-by: 3gf8jv4dv <3gf8jv4dv@gmail.com>
Co-authored-by: Glavo <zjx001202@gmail.com>

HMCLCore/src/main/java/org/jackhuang/hmcl/game/World.java

@@ -275,6 +275,13 @@ public final class World {
         }
     }
 
+    public void delete() throws IOException {
+        if (isLocked()) {
+            throw new WorldLockedException("The world " + getFile() + " has been locked");
+        }
+        FileUtils.deleteDirectory(file);
+    }
+
     public CompoundTag readLevelDat() throws IOException {
         if (!Files.isDirectory(file))
             throw new IOException("Not a valid world directory");