Support OBJECT data type

Author: zerolbsony

integration-test/src/test/java/org/apache/iotdb/relational/it/schema/IoTDBAlterColumnTypeIT.java

@@ -127,12 +127,6 @@ public void testWriteAndAlter()
 
     for (TSDataType from : typesToTest) {
       for (TSDataType to : typesToTest) {
-        if (from == TSDataType.TEXT && to == TSDataType.STRING) {
-          //          continue;
-        } else {
-          continue;
-        }
-
         if (from != to && to.isCompatible(from)) {
           System.out.printf("testing %s to %s%n", from, to);
           doWriteAndAlter(from, to);

iotdb-core/datanode/src/main/java/org/apache/iotdb/db/utils/datastructure/AlignedTVList.java

@@ -452,6 +452,7 @@ private Object getObjectByValueIndex(int rowIndex, int columnIndex) {
       case STRING:
       case BLOB:
       case TEXT:
+      case OBJECT:
         return ((Binary[]) columnValues.get(arrayIndex))[elementIndex];
       default:
         throw new IllegalArgumentException(dataTypes.get(columnIndex) + " is not supported");