feat:创建挂单数据库，和迁移文件

android/app/src/main/java/io/flutter/plugins/facediscern/database/DatabaseHelper.java

@@ -15,7 +15,7 @@ public class DatabaseHelper extends SQLiteOpenHelper {
 
     private static final String DATABASE_PATH = "pj_cashier/database";
     private static final String DATABASE_NAME = "cash_register.db";
-    private static final int DATABASE_VERSION = 2;
+    private static final int DATABASE_VERSION = 3;
 
     public DatabaseHelper(Context context) {
         super(context, getCustomDatabasePath(context), null, DATABASE_VERSION);