Handle description and tag updates

Author: harshach

catalog-rest-service/src/main/java/org/openmetadata/catalog/jdbi3/TableRepository.java

@@ -825,10 +825,12 @@ private void updateColumns(
       for (Column deleted : deletedColumns) {
         if (addedColumnMap.containsKey(deleted.getName())) {
           Column addedColumn = addedColumnMap.get(deleted.getName());
-          if (addedColumn.getDescription().isEmpty() && !deleted.getDescription().isEmpty()) {
+          if ((addedColumn.getDescription() == null || addedColumn.getDescription().isEmpty())
+              && (deleted.getDescription() == null || !deleted.getDescription().isEmpty())) {
             addedColumn.setDescription(deleted.getDescription());
           }
-          if (addedColumn.getTags().isEmpty() && !deleted.getTags().isEmpty()) {
+          if ((addedColumn.getTags() == null || addedColumn.getTags().isEmpty())
+              && (deleted.getTags() == null || !deleted.getTags().isEmpty())) {
             addedColumn.setTags(deleted.getTags());
           }
         }