Add ScalarDB Dao and related files

core/src/main/java/com/scalar/db/common/error/CoreError.java

@@ -1015,6 +1015,18 @@ public enum CoreError implements ScalarDbError {
       "Handling the before-preparation snapshot hook failed. Details: %s",
       "",
       ""),
+  DATA_LOADER_ERROR_CRUD_EXCEPTION(
+      Category.INTERNAL_ERROR,
+      "0047",
+      "Something went wrong while trying to save the data. Details: %s",
+      "",
+      ""),
+  DATA_LOADER_ERROR_SCAN(
+      Category.INTERNAL_ERROR,
+      "0048",
+      "Something went wrong while scanning. Are you sure you are running in the correct transaction mode? Details: %s",
+      "",
+      ""),
 
   //
   // Errors for the unknown transaction status error category