Fix ore dropping and implement subfields

src/main/java/emu/grasscutter/data/server/DropSubfieldMapping.java

@@ -0,0 +1,10 @@
+package emu.grasscutter.data.server;
+
+import lombok.Data;
+
+@Data
+public class DropSubfieldMapping {
+    private int dropId;
+    private int levelLimit;
+    private int itemId;
+}

src/main/java/emu/grasscutter/data/server/DropTableExcelConfigData.java

@@ -0,0 +1,24 @@
+package emu.grasscutter.data.server;
+
+import lombok.Data;
+
+@Data
+public class DropTableExcelConfigData {
+    private int id;
+    private int randomType;
+    private int dropLevel;
+    private DropVectorEntry[] dropVec;
+    private int nodeType;
+    private boolean fallToGround;
+    private int sourceType;
+    private int everydayLimit;
+    private int historyLimit;
+    private int activityLimit;
+
+    @Data
+    public class DropVectorEntry {
+        private int itemId;
+        private String countRange;
+        private int weight;
+    }
+}

src/main/java/emu/grasscutter/data/server/SubfieldMapping.java

@@ -0,0 +1,15 @@
+package emu.grasscutter.data.server;
+
+import lombok.Data;
+
+@Data
+public class SubfieldMapping {
+    private int entityId;
+    private SubfieldMappingEntry[] subfields;
+
+    @Data
+    public class SubfieldMappingEntry {
+        private String subfieldName;
+        private int drop_id;
+    }
+}